System and method for improved gas recirculation in surgical trocars with pneumatic sealing

ABSTRACT

Systems for insufflation and recirculation of insufflation fluid in a surgical procedure include a control unit having a fluid pump, a supply conduit, a return fluid conduit and a pressure-controlled valve. The pressure-controlled valve is in fluid communication with an insufflation gas supply, the supply conduit and the return conduit and is adapted and configured to respond to pressure control signals to adjust position and thereby system flow parameters, to reduce entrainment of air from the surrounding environment, and to increase the concentration of insufflation gas in an operative space, and/or to reduce an overpressure condition in the operative space.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/268,408 filed May 2, 2014, which is a continuation of U.S. patentapplication Ser. No. 12/587,584 filed Oct. 9, 2009, now U.S. Pat. No.8,715,219, which claims the benefit of priority to U.S. PatentApplication Ser. No. 61/104,448, filed Oct. 10, 2008.

BACKGROUND OF THE INVENTION Field of the Invention

The present application relates to systems and devices for surgicalaccess, and is particularly directed devices adapted and configured tocreate a fluidic seal, and to systems for supplying pressurized fluid tosuch devices, which are also capable of recirculating such pressurizedfluid. Surgical access devices configured for creating a fluidic sealfor surgical access are set forth in the following applications, whichare incorporated herein by reference in their entirety: U.S. patentapplication Ser. No. 11/517,929, filed Sep. 8, 2006, U.S. Pat. Nos.7,338,473, 7,285,112, 7,182,752.

Description of Related Art

Laparoscopic, or “minimally invasive” surgical techniques are becomingincreasingly more common. Benefits of such procedures include reducedtrauma to the patient, reduced opportunity for infection, and decreasedrecovery time. Such procedures within the abdominal cavity are typicallyperformed through a device known as a trocar or cannula, whichfacilitates the introduction of laparoscopic instruments into theabdominal cavity of a patient.

Additionally, such procedures commonly involve filling or “insufflating”the abdominal (peritoneal) cavity with a pressurized fluid, such ascarbon dioxide, to create what is referred to as a pneumoperitoneum. Theinsufflation can be carried out by a trocar equipped to deliverinsufflation fluid, or by a separate insufflation device, such as aninsufflation needle. Introduction of surgical instruments into thepneumoperitoneum without a substantial loss of insufflation gas isdesirable, in order to maintain the pneumoperitoneum.

During typical laparoscopic procedures, a surgeon makes three to foursmall incisions, usually no larger than about twelve millimeters each,which are typically made with the trocar devices themselves, typicallyusing a separate inserter or obturator placed therein. Followinginsertion, the inserter is removed, and the trocar allows access forinstruments to be inserted into the abdominal cavity. Typical trocarsoften provide means to insufflate the abdominal cavity, so that thesurgeon has an open interior space in which to work.

The trocar must provide a means to maintain the pressure within thecavity by sealing between the trocar and the surgical instrument beingused, while still allowing at least a minimum freedom of movement of thesurgical instruments. Such instruments can include, for example,scissors, grasping instruments, occluding instruments, cauterizingunits, cameras, light sources and other surgical instruments. Sealingelements or mechanisms are typically provided on trocars to prevent theescape of insufflation gas. Sealing elements or mechanisms typicallyinclude a duckbill-type valve made of a relatively pliable material, toseal around an outer surface of surgical instruments passing through thetrocar. However, sealing in this manner is not usually complete, suchseals cannot seal between multiple instruments, and such seals alsoinhibit free movement of the surgical instruments and/or removal oftissue through the trocar. Such seals are also vulnerable to damageduring the surgical procedure. Alternatively, a flapper valve orspring-loaded trap door can be used. However, these types of mechanicalvalves suffer from similar drawbacks.

Most valves, and particularly duckbill-type valves, which includeresilient valve members that directly contact surgical instruments, notonly interfere with the movement of surgical instruments, but reduce theability of a surgeon to accurately sense the patient anatomy on whichthe surgeon is operating. Minimally invasive surgical procedures arecarried out with a visualization aid such as a camera, and as a result,depth perception on the part of the surgeon is inhibited. Moreover, whenthe endoscope passes through mechanical seals, lenses thereof can bedirtied, typically with smears appearing, resulting in further visiondifficulty. The absence of mechanical seals also allows swabs andspecimens to be extracted without excessive interference. Additionally,the ability to physically sense resistance of structures and of tissuesthrough movement of the surgical instruments plays an important role ina successful and safe surgical procedure. Frictional forces imparted onsurgical instruments by contact of the aforementioned mechanical valvescan mask the sensory signals, i.e., the haptic perception, that thesurgeon might otherwise use to determine precisely what is occurring atthe opposite end of the surgical instruments being used.

Additionally, conventional surgeries typically involve the use ofcautery and suction devices, each of which presents disadvantages,particularly when used in minimally invasive procedures underinsufflation, where a patient's body cavity becomes, essentially, aclosed, pressurized space. Accordingly, smoke created by cautery devicesand the like fill the closed space with particulates that inhibit thesurgeon's view of the operative site. Although devices, to evacuatesmoke from a surgical site have been developed, there are disadvantagesto such systems, including that one or two additional incisions must bemade to access the respective body cavity of the patient.

Additionally the use of suction devices, such as those used to removeliquids at the operative site, disturb the pressure balance in thepatient's body cavity, undesirably remove the carbon dioxide gas usedfor insufflation, and at the same time cause external air (from theoperating room) to be drawn into the surgical site, altering theconcentration of carbon dioxide gas to other gasses in the body cavity,which is typically undesirable for the safety of the patient.

Accordingly, improvements to sealing technologies that allowunencumbered access while maintaining a pneumoperitoneum, are desired.The present invention provides a solution for these problems.

SUMMARY OF THE INVENTION

The purpose and advantages of the present invention will be set forth inand apparent from the description that follows. Additional advantages ofthe invention will be realized and attained by the devices, systems andmethods particularly pointed out in the written description and claimshereof, as well as from the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the invention, as embodied, the invention includes, in oneembodiment, a system for insufflation and recirculation of insufflationfluid from a surgical operative environment, such as a patient'sabdominal cavity. The system includes a control unit having a fluidpump, a supply conduit, a return fluid conduit and a pressure-controlledvalve. The fluid pump is adapted and configured to circulateinsufflation fluid through the system. The supply conduit is in fluidcommunication with an output of the fluid pump and configured andadapted for delivering pressurized insufflation fluid to an output portof the control unit. The return conduit is in fluid communication withan input of the fluid pump for delivering insufflation fluid to thefluid pump and is configured and adapted for returning insufflationfluid from an input port of the control unit. The pressure-controlledvalve is in fluid communication with the supply conduit and the returnconduit, and is adapted and configured to receive a control signal andrespond to the control signal by adjusting as follows.

The pressure-controlled valve responds to a low pressure control signalby opening, to place the supply conduit and the return conduit in fluidcommunication with one another, to reduce entrainment of air from thesurrounding environment and to place the insufflation gas supply influid communication with the return conduit to increase theconcentration of insufflation gas in the system.

The pressure-controlled valve responds to a first high pressure controlsignal by opening, placing the supply conduit and the return conduit influid communication with one another.

The pressure-controlled valve responds to a second high pressure controlsignal, corresponding to a pressure higher than the first high pressurecontrol signal, by additionally opening a dump valve to release pressurefrom the system.

In absence of a control signal, the pressure-controlled valve can beconfigured to remain in a closed state. The pressure-controlled valvecan be additionally in fluid communication with a pressure sensingconduit, adapted and configured for communicating a control signal,corresponding to a pressure value at a distal end thereof, to thepressure-controlled valve.

In accordance with one aspect of the invention, a low pressure, causinga low pressure control signal, can be defined as an abdominal pressureat or below about 4.0 mmHg from a set pressure, a first high pressure,causing a first high pressure control signal, can be defined as anabdominal pressure at or above 4.0 mmHg from the set pressure, and asecond high pressure, higher than the first high pressure, causing asecond high pressure control signal, can be defined as an abdominalpressure at or above about 160% of the set pressure.

The pressure-controlled valve can be a mechanical diaphragm valve, withthe pressure sensing conduit in fluid communication with a pressuresensing chamber of the pressure-controlled valve. Alternatively,pressure sensing can be accomplished by way of an electronic pressuretransducer electrically coupled to an electromechanical valve.

The system can further include a trocar having an elongated bodydefining a lumen therein, a nozzle operatively associated with the bodyfor directing pressurized fluid into the lumen, and a fluid returnplenum adapted and configured to collect spent insufflation fluid. Anozzle supply port is in fluid communication with the nozzle, fordelivering a pressurized flow of insufflation fluid to the nozzle, andadapted and configured to receive pressurized insufflation fluid from anoutput port of the control unit. A fluid return port is in fluidcommunication with the fluid return plenum, and is adapted andconfigured for returning insufflation fluid from the trocar to an inputport of the control unit. The trocar can further include a pressuresensing chamber adapted and configured to be in fluid communication witha patient's abdominal cavity and with the pressure-controlled valve ofthe control unit.

Systems in accordance with the invention can further include aconnection kit having a plurality of connecting conduits, one or morefilters, and one or more connectors. The plurality of connectingconduits are adapted and configured to connect the nozzle supply port ofthe trocar to the output port of the control unit, to connect the fluidreturn port of the trocar to the input port of the control unit, and toconnect the pressure sensing chamber of the trocar to thepressure-controlled valve of the control unit. The filter element isprovided in fluid communication with at least one of the connectingconduits. The one or more connectors are disposed at each end of theconnecting conduits, and are configured and adapted to mutually engagethe connection kit with the trocar at one end, and with the control unitat its opposite end.

The system can include a surgical insufflator adapted and configured toreceive, through an input port thereof, a supply of insufflation gasfrom a source, an output port of the insufflator being in fluidcommunication with a pressure sensor for operating thepressure-controlled valve and with a patient's abdominal cavity, theinsufflator being adapted and configured to sense pressure within theabdominal cavity and to provide insufflation fluid thereto.

The control unit can include the surgical insufflator incorporated intoa single housing. Moreover, systems in accordance with the invention canfurther include first and second trocars. The first trocar can includean elongated body defining a lumen therein, a nozzle operativelyassociated with the body for directing pressurized fluid into the lumento form a fluid seal thereacross, a fluid return plenum adapted andconfigured to collect spent insufflation fluid, a nozzle supply port influid communication with the nozzle, for delivering a pressurized flowof insufflation fluid to the nozzle, adapted and configured to receivepressurized insufflation fluid from an output port of the control unit,and a fluid return port in fluid communication with the fluid returnplenum, adapted and configured for returning insufflation fluid from thetrocar to an input port of the control unit. The second trocar can be influid communication with a surgical insufflator adapted and configuredto receive, through an input port thereof, a supply of insufflation gasfrom a source, the insufflator being adapted and configured to sensepressure within an abdominal cavity and to deliver pressurizedinsufflation fluid thereto through the second trocar. The second trocarcan be used as a primary trocar for insufflation of the abdomen prior toactivation of the first trocar, or vice versa, as desired.

In accordance with the invention, the insufflator and thepressure-controlled valve can each be independently in fluidcommunication with a patient's abdominal cavity, and each are adaptedand configured to sense abdominal pressure therein.

In accordance with a further aspect of the invention a trocar for use ina minimally-invasive surgical procedure is provided. The trocar includesan elongated body, a fluid supply plenum, a supply port, a nozzle and afluid return port. The body defines a lumen therein, the proximal endportion of the body defining a housing, and a fluid supply plenum isdefined in the housing. The supply port is in fluid communication withthe fluid supply plenum, and is adapted and configured to receivepressurized insufflation fluid from a recirculation device and todeliver the pressurized insufflation fluid to the fluid supply plenum.The nozzle is in fluid communication with the fluid supply plenum andthe lumen, and is configured and adapted for directing pressurized fluidinto the lumen. The fluid return plenum is defined in the housing andarranged distal the fluid supply plenum. The fluid return plenum isadapted and configured to collect spent insufflation fluid. The fluidreturn port is in fluid communication with the fluid return plenum, andis adapted and configured for returning insufflation fluid from thetrocar to a recirculation device.

The trocar can further include sound attenuation elements arranged inthe fluid return plenum. The sound attenuation elements can be selectedfrom the group consisting essentially of baffles and sound-absorbingmaterial, such as foam, for example. The trocar can further includesound attenuation elements arranged in a proximal sound attenuationchamber arranged proximal to the fluid supply plenum.

In accordance with the invention, the fluid return plenum can be definedbetween a distal end of the housing and a first substantially annularinsert placed in the housing, and the fluid supply plenum can be definedbetween the annular insert and a second substantially annular insert.The second substantially annular insert can have a substantially tubularmember extending distally therefrom, with the nozzle being definedbetween the substantially tubular member and an central portion of thefirst substantially annular insert.

The trocar can further include a pressure sensing chamber adapted andconfigured to be placed in fluid communication with a patient'sabdominal cavity. The pressure sensing chamber can be in fluidcommunication with a pressure sensing port defined on the trocar, forconnecting to a pressure sensing element, such as a diaphragm orelectronic pressure transducer, for example.

In accordance with another embodiment of the invention, a trocar for usein a minimally-invasive surgical procedure includes an elongated bodyand first, second, third and fourth inserts. The proximal end portion ofthe body defines a housing. The first insert has a substantially tubularconfiguration extending through the body and defining a pressure sensingchamber therebetween. The pressure sensing chamber is adapted andconfigured to be placed in fluid communication with a patient'sabdominal cavity. The second insert is arranged in the housing proximalthe first insert, and has a substantially annular configuration and aplurality of apertures defined therein for allowing passage of spentinsufflation fluid to pass therethrough. The third insert is arranged inthe housing proximal the second insert, and has a substantially annularconfiguration. The housing, first, second and third inserts definerespective walls of a fluid return plenum, which is adapted andconfigured to collect spent insufflation fluid. The fourth insert isarranged in the housing proximal the third insert, and has asubstantially annular configuration and substantially tubular memberextending distally therefrom. A nozzle defined between the substantiallytubular member and a central portion of the third insert. The housingand third and fourth inserts define a fluid supply plenum in fluidcommunication with the nozzle.

The trocar can further include sound attenuation elements arranged in aproximal sound attenuation chamber arranged proximal to the fluid supplyplenum. The first insert can include at least one aperture defined inthe sidewall thereof to attenuate a sound created by airflow through thefirst insert.

In accordance with still another embodiment of the invention, a trocarfor use in a minimally-invasive surgical procedure is provided. Thetrocar has an elongated body, a fluid return plenum, and a fluid supplyplenum. The body has a lumen extending therethrough, with the proximalend portion of the body defining a housing. The fluid return plenum isdefined in the housing and is adapted and configured to collect spentinsufflation fluid. The fluid supply plenum is defined in the housingand arranged proximal the fluid return plenum. The fluid supply plenumis adapted and configured to deliver pressurized insufflation fluid to anozzle in fluid communication therewith. The nozzle is configured andadapted for directing pressurized fluid into the lumen.

In accordance with this embodiment or other embodiments set forthherein, the trocar can further include a pressure sensing chamberdefined in a distal end portion of the housing, distal the fluid returnplenum, adapted and configured to be placed in fluid communication witha patient's abdominal cavity.

In accordance with still another embodiment of the invention, a trocarfor use in a minimally-invasive surgical procedure is provided having anelongated body, a pressure sensing chamber, a safety valve and a fluidsupply plenum. The elongated body has a lumen extending therethrough,and the proximal end portion of the body defines a housing. The pressuresensing chamber is defined in a distal end portion of the housing, andis adapted and configured to be placed in fluid communication with apatient's abdominal cavity. The safety valve is arranged in the housing,is in fluid communication with the pressure sensing chamber andconfigured and is adapted to relieve pressure from within a patient'sabdominal cavity in a case of abdominal pressure exceeding apredetermined limit. The fluid supply plenum is defined in the housing,arranged proximal the fluid return plenum, and is adapted and configuredto deliver pressurized insufflation fluid to a nozzle in fluidcommunication therewith. The nozzle is configured and adapted fordirecting pressurized fluid into the lumen.

If desired, a pressure relief valve in direct fluid communication to theoutside of the trocar, and the surrounding environment, can also be incommunication with the return plenum. Such a pressure relief valveprevents outside air from being sucked into the plenum but allowsoverpressure fluid to escape, harmlessly.

In accordance with the invention, a method of sealing a pressurizedcavity of a patient for a surgical procedure is provided. The methodincludes the steps of providing a trocar for use in a minimally invasivesurgical procedure, supplying a flow of pressurized fluid to the fluidsupply plenum, recovering a flow of spent insufflation fluid from thefluid return plenum, recycling at least a portion of the spentinsufflation fluid received from the return plenum to the fluid supplyplenum, inserting a surgical instrument through the lumen of the trocar,whereby the pressurized fluid supplied to the fluid supply plenum formsa pressure barrier around the surgical instrument, thereby inhibitingloss of pressure within the cavity of the patient. In accordance withthis method, the trocar includes an elongated body, a fluid returnplenum and a fluid supply plenum. The elongated body has a lumenextending therethrough, and the proximal end portion of the body definesa housing. The fluid return plenum is defined in the housing, and isadapted and configured to collect spent insufflation fluid. The fluidsupply plenum is defined in the housing, is arranged proximal the fluidreturn plenum, and is adapted and configured to deliver pressurizedinsufflation fluid to a nozzle in fluid communication therewith. Thenozzle is configured and adapted for directing pressurized fluid intothe lumen. The method can further include the step of filtering theinsufflation gas during the step of recycling. Additionally, the step ofinserting a second surgical instrument through the lumen of the trocar,whereby the pressurized fluid supplied to the trocar seals around andbetween the first and second surgical instruments, preventing loss ofpressure within the cavity of the patient can be included.

It is noted that although the term “trocar” is used herein, the term isintended to mean a surgical access device, that allows insertion ofsurgical instruments, a surgeon's hand or the like, into a surgicalcavity, while maintaining insufflation pressure.

It is to be understood that any feature described in connection with anyparticular embodiment set forth herein can advantageously be applied toother embodiments set forth herein, or indeed, to variations ofembodiments not specifically set forth herein, and still be in keepingwith the spirit of the present invention. It is also to be understoodthat both the foregoing general description and the following detaileddescription are exemplary and are intended to provide furtherexplanation of the invention claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those having ordinary skill in the art to which the subjectinvention pertains will more readily understand how to make and use thedevices and systems of the subject invention, preferred embodimentsthereof will be described in detail hereinbelow, with reference to thedrawings, wherein:

FIG. 1 is an isometric view of a trocar in accordance with oneembodiment of the present invention;

FIG. 2 is a cross-sectional view of the trocar of FIG. 1.

FIG. 3 is an enlarged view of the respective portion of FIG. 2,illustrating the nozzle in detail;

FIG. 4 is a cross-sectional view of a trocar in accordance with afurther embodiment the present invention;

FIG. 5 is a cross-sectional view of the trocar of FIG. 4 with anobturator inserted therethrough;

FIG. 6 is a cross-sectional view of a trocar in accordance with still afurther embodiment the present invention;

FIG. 7 is a cross-sectional view of the trocar of FIG. 6, rotated aboutits longitudinal axis;

FIG. 8A is a cross-sectional view of a trocar in accordance with stillanother embodiment the present invention having proximal and distalsound attenuation chambers in the housing thereof;

FIG. 8B is a cross-sectional view of a trocar in accordance with stillanother embodiment the present invention having proximal and distalsound attenuation chambers in the housing thereof, and a proximaladapter portion for engaging a removable cap;

FIG. 9A is a cross-sectional view of a trocar in accordance with afurther embodiment the present invention, having a proximal ball valveand a proximally arranged fluid collection chamber;

FIG. 9B is an enlarged partial cross-sectional view of the trocar ofFIG. 9A, illustrating detail in the proximal end portion thereof;

FIG. 10 is a cross-sectional view of a further trocar in accordance withthe present invention, having a proximal fluid collection chamber;

FIG. 11 is a cross-sectional view of a trocar in accordance with afurther embodiment the present invention, having a safety valveincorporated therewith and a removable proximal cap;

FIG. 12 is an enlarged partial cross-sectional view of the trocar ofFIG. 11, illustrating detail in the proximal end portion thereof;

FIG. 13 is a cross-sectional view of the cap of the embodiment of FIGS.11 and 12;

FIG. 14 is an isometric view of one embodiment of an insufflation andcirculation system in accordance with the invention;

FIG. 15A is an example schematic representation of the main componentsincluded within the system of FIG. 14;

FIG. 15B is an alternate embodiment of the system of FIGS. 14 and 15A,including an integral pressure dumping valve;

FIG. 16 is an alternate embodiment of the system of FIGS. 14 and 15,wherein main components of the system are housed in a single unit;

FIG. 17 is an isometric view of a second embodiment of an insufflationand circulation system in accordance with the invention;

FIG. 18 is an example schematic representation of the main componentsincluded within the system of FIG. 17;

FIG. 19 is an isometric view of an alternate configuration of aninsufflation and recirculation system in accordance with the invention;

FIG. 20 is an isometric front view of a filter housing in accordancewith the invention;

FIG. 21 is an isometric side view of the filter element of FIG. 20;

FIG. 22 is another isometric side view of the filter element of FIG. 20;

FIG. 23 is an isometric view of a connection between a tube set and atrocar, in accordance with the invention;

FIG. 24 is an isometric view of a tube end connector in accordance withthe invention;

FIG. 25 is a cross-sectional view of a further embodiment of a trocar inaccordance with the invention connected with a tube set;

FIG. 26 is an alternate embodiment of an insufflation and recirculationsystem in accordance with the invention, having a back pressure controlvalve;

FIG. 27 is a further alternate embodiment of an insufflation andrecirculation system in accordance with the invention, having a backpressure control valve, a pressure sensor and a pressure dump valve;

FIG. 28 is a schematic illustration of a recirculation system inaccordance with the invention having bypass and insufflation gas floodcapability;

FIG. 29 is a schematic illustration of a recirculation system inaccordance with the invention similar to the embodiment of FIG. 28, bututilizing an electromechanical valve;

FIG. 30 illustrates a system in accordance with the invention having aninsufflation and recirculation unit and a plurality of air-sealedtrocars provided in a “daisy chain” arrangement;

FIG. 31 illustrates a system in accordance with the invention having aninsufflation and recirculation unit and a plurality of air-sealedtrocars provided in parallel.

FIG. 32 is a schematic view of a recirculation system in accordance withthe invention including a plurality of fluid pumps, a heat exchanger, aplurality of pressure relief valves and filters, among other features;

FIG. 33a is a schematic view of a recirculation system in accordancewith the invention including a plurality of fluid pumps, an alternatepressure sensing arrangement using a venturi device, and a plurality ofpressure relief valves, wherein at least one of such valves iselectromechanical in nature;

FIG. 33b is an enlarged schematic of a venturi device for use inconjunction with the invention for providing accurate and continuouspressure readings within the subject systems;

FIG. 34 is an isometric view of an adapter in accordance with theinvention for adapting a multi-lumen tube set for use with systemsaccording to the invention for use with a single lumen standardinsufflation device, such as a veress needle or standard insufflationtrocar;

FIG. 35 is a cross-sectional view of the adapter of FIG. 34 showing aninternal passageway;

FIG. 36 is a side view of a surgical access device in accordance withthe invention;

FIG. 37 is an opposite side view of the surgical access device of FIG.36, with a proximal cap provided thereon;

FIG. 38 is a side view of the surgical access device of FIGS. 35 and 36,with a cap provided thereon, assembled with an insertion device forinsertion into a patient;

FIG. 39 is a partial cutaway view of the insertion device of FIG. 38, inthe assembly of FIG. 38;

FIG. 40 is an opposite side view from FIG. 38 of the assembly of FIG.38;

FIG. 41 is a top view of the assembly of FIG. 38;

FIG. 42 is a bottom view of the assembly of FIG. 38;

FIG. 43 is a cross-sectional view of the surgical access device of FIG.36;

FIG. 44 is an enlarged cross-sectional view of the proximal end of thesurgical access device of FIG. 36;

FIG. 45 is an enlarged cross-sectional view of the distal end of thesurgical access device of FIG. 36;

FIG. 46-51 are isometric views of various components of the trocar ofFIG. 36;

FIGS. 52a and 52b illustrate details of one nozzle arrangement for thesubject surgical access devices;

FIGS. 53-57 include various views and components for an alternate nozzlearrangement for the subject surgical access devices;

FIG. 58-59 illustrate one embodiment of a closeable proximal end cap forsurgical access devices in accordance with the invention; and

FIGS. 60-63 illustrate an alternate embodiment of a closeable proximalend cap for surgical access devices in accordance with the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The devices, systems and methods presented herein may be used forcreating and maintaining a surgical pathway through the abdominal wallof a patient undergoing minimally invasive surgery. The presentinvention is particularly suited for minimally invasive surgeriesperformed under insufflation, such as laparoscopic removal of a gallbladder.

For the purposes of explanation and illustration, and not limitation,referring now to the drawings, wherein like reference numerals identifysimilar structural aspects of the subject trocars and systems therefor,a first exemplary embodiment of a trocar in accordance with theinvention is shown in FIGS. 1-3, and is designated generally byreference character 100. Other embodiments of trocars in accordance withthe invention, related systems or aspects thereof, are provided insubsequent figures, which are described in detail below.

FIG. 1 is a side view, and FIG. 2 is cross-sectional view of a trocar100 constructed in accordance with the invention. The trocar includes acentral lumen 107, which is defined by various elements, and whichextends longitudinally, through the center of the trocar 100. The trocar100 includes a body 110, including a housing 115 defined in the proximalend portion thereof. A connection block 117 extends from the housing 115and facilitates connection between the trocar 100 and fluid conduitsconnected thereto, as best shown in FIG. 2.

Defined within the housing 115 are a pressure sensing chamber 111including a pressure sensing plenum 111 a, which is in fluidcommunication with a pressure sensing channel 111 b. The pressuresensing chamber 111 is defined between the body 110 and a body insert120, including a substantially tubular portion 120 b and a substantiallyannular portion 120 a. This arrangement of the pressure sensing chamberallows the remainder of the system, described hereinbelow, to be influid communication with the abdominal cavity, so that the abdominalpressure can be monitored and controlled. As shown in FIG. 2, a pressuresensing conduit 212 is in fluid communication with the pressure sensingchamber 111, which in-turn connects with a control unit of the system,described in more detail hereinbelow. Further, apertures 125 can beformed in the wall of the tubular portion 120 b of the body insert 120.These apertures 125 can be arranged so as to alter the acousticproperties of the tubular portion 120 b, by reducing the effectivelength of the tubular portion 120 b. Accordingly, the wavelength ofsound produced by fluid passing through the lumen 107 can be adjusted sothat it is more easily canceled out by other sound attenuation elements,such as those housed within the cap 160.

The annular portion 120 a of the body insert 120 separates the pressuresensing chamber 111 and a fluid return plenum 121. The fluid returnplenum is further defined by the housing 115 on its outer periphery, asecond diffuser insert 130 on its inner periphery, and an annular insert140 having a substantially annular configuration. The second diffuserinsert 130 serves in-part, to maintain spacing between the body insert120 and the annular insert 140. The fluid return plenum 121 allows forcollection of spent insufflation fluid—fluid moving proximally,returning from within the lumen of the tubular portion 120 b of the bodyinsert 120. Apertures defined in the second insert promote evenevacuation of fluid from about the circumference of the lumen 107 in theregion of the fluid return plenum 121. Fluid is removed from the fluidreturn plenum 121 through a fluid return conduit 222 and can berecirculated, such as through the systems embodied in FIGS. 14-18.

The fourth insert 150 includes a substantially annular portion 150 a anda substantially tubular portion 150 b. One or more standoffs 154 can beprovided on the fourth insert 15, or alternatively the annular insert140, to maintain spacing of the fluid supply plenum 141 definedtherebetween. Additionally, a nozzle 155 is defined between the annularinsert 140 and a fourth insert 150. The precise geometry of the annularinsert 140 and fourth insert 150, and the spacing therebetween allow fora continuous stream of fluid which serves to effectively seal the lumen107, and inhibit escape of insufflation fluid. The lower outercircumferential edge 159 of the tubular portion 150 b of the fourthinsert 150 is angled inward, which directs the continuous stream offluid centrally. The fluid follows the contour of this surface 159, andis thus directed centrally, at least in part due to the Coanda effect.Fluid is supplied to the fluid supply plenum 141 through a fluid supplyconduit 242. Preferably, the fluid return conduit 222 is larger indiameter than the fluid supply conduit 242, as returning fluid isdepressurized and therefore occupies an increased volume. To maintainequivalent mass flow rates for supplied and returned fluid, the diameterof the fluid return conduit 222 should have a larger diameter.Pressurized insufflation fluid can be supplied to the trocar 1000through systems such as those embodied in FIGS. 14-18.

Additionally, any of the inserts can be sealed to the housing 115 tocreate fluid-tight seals therebetween. In the illustrated embodiment,grooves 152 are provided between the body insert 120, annular insert 140and fourth insert 150 and the housing 115, respectively. In thesegrooves, a sealing element, such as an O-ring can be placed.

A cap 160 is provided at the proximal end of the trocar 100. Asillustrated in FIG. 1, the cap 160 can be affixed to the housing 115 byway of a snap fit arrangement. In this case, protrusions on the cap 160each engage a pawl 119 on the housing 115. Naturally, any other suitableconnection can be used, including but not limited to friction fit, alatch, adhesive, solvent welding, ultrasonic welding, heat welding andmechanical fasteners such as a hook- and loop fastener. Accordingly, thecap 160 can be permanently installed or can be removable from theremainder of the trocar 100. Further, as illustrated, the cap 160 canextend past the joint between the fourth insert 150 and the housing 115,effectively preventing proximal movement of any insert held within thehousing 115.

The cavity 161 defined by the cap 160, with the exclusion of the volumenecessary in the lumen 107 for passage of surgical implements, caninclude sound absorbing material and/or baffles to reduce noise emittedfrom the trocar 100. In combination with the apertures 125 formed in thebody insert 120, sound emitted can be reduced significantly by mutuallytuning these sound attenuating features.

FIGS. 4 and 5 illustrate a second embodiment of a trocar 400 constructedin accordance with the invention, with FIG. 5 illustrating the trocar400 having an obturator 599 inserted therein. Distinguishing of thisembodiment, as compared with the embodiment of FIGS. 1-3, is the fluidreturn plenum 421. Instead of providing an annular insert having aplurality of apertures formed therein, a plurality of baffles 425 areprovided, which act as a standoff to maintain spacing within the housing415 of the trocar 400, and can be adapted to enhance noise reduction byabsorbing sound. Additionally, sound absorbing material can be laced inthe fluid return plenum 421 to further enhance noise reduction.

As with the embodiment of FIGS. 1-3, the embodiment of FIGS. 4 and 5includes a body insert 420 inserted into the body 410. The baffles 425are integrally formed with an insert, such as the body insert 420 orannular insert 440, but alternatively can be formed independently andseparately inserted in the housing 415. The annular insert 440, inconjunction with a nozzle insert 450, together define the nozzle 455 anddefine the fluid supply plenum 441. Similarly, the fluid return plenum421 is defined on the distal side of the annular insert 440, and is influid communication with a fluid return port 427. Further, a cap 460 canbe provided at the proximal end portion of the trocar 400, and caninclude sound attenuation materials therein.

As shown in FIG. 5, the obturator 599 has been designed for therecirculation system and devices disclosed herein. The obturator hasO-rings 501 proximal and distal to the jets that fit tightly into thecannula. With the obturator 599 installed the O-rings 501 maintain aseal against gas escaping from the abdomen through the trocar 400. TheO-rings 501 also contain the jet flow within the trocar 400. The supplycan be pumped to the trocar prior to insertion. The gas will passthrough the jets and out the return line without creating any blowingeffects external to the trocar. Once the trocar 400 is inserted into thepatient, the obturator 599 can be removed and the air seal will beestablished without losing pneumoperitoneum.

FIGS. 6 and 7 illustrate a third representative embodiment of a trocar600 in accordance with the invention. The trocar 600 is similar to theforegoing embodiments, but does not include either a pressure senseplenum, or a proximal cap. The trocar 600 includes a body 610, having ahousing 615 arranged at the proximal end portion thereof. Baffles 643,an annular insert 640 and nozzle insert 650, respectively define, inconjunction with the housing 615, a fluid return plenum 621, a fluidsupply plenum 641, a central lumen 607 and a nozzle 655. The nozzleinsert 650 is formed so as to have a depressed region 656 which helpsguide surgical instruments to the lumen 607. A return fluid port 627(FIG. 6) is formed through the housing 615 and is in fluid communicationwith the fluid return plenum. A fluid supply port 647 (FIG. 7) issimilarly formed through the housing 615 and is in fluid communicationwith the fluid supply plenum 641.

FIG. 8A illustrates yet another trocar 800A constructed in accordancewith the present invention. The trocar 800A includes a body 810, havinga housing 815 arranged at the proximal end portion thereof. Distalbaffles 829, an annular insert 840 and nozzle insert 850, respectivelydefine, in conjunction with the housing 815, a fluid return plenum 821,a fluid supply plenum 841, a central lumen 807 and a nozzle 855. Thenozzle insert 850 is formed so as to have a depressed region 856 whichhelps accommodate proximal baffles 869 within the chamber 861 defined bya proximal cap 860. A reduced aperture 868 can be provided at theproximal end portion of the cap 860. Optionally, an annular seal can beprovided therein in order to further seal the lumen 807 against asurgical instrument when the surgical instrument is insertedtherethrough.

A return fluid port 827 is formed through the housing 815 and is influid communication with the fluid return plenum 821. A fluid supplyport is similarly formed through the housing 815 and is in fluidcommunication with the fluid supply plenum 841. As with the foregoingembodiment, no pressure sense chamber is provided, but as is the casewith the foregoing embodiment or any embodiment set forth herein, suchpressure sense capability can be imparted by providing such a chamber inanother, similar trocar or as a separately inserted needle into theabdomen of the patient.

FIG. 8B illustrates a trocar 800B having an alternate arrangement of theproximal end thereof, but otherwise similar to trocar 800A of FIG. 8A.The trocar 800B includes a body 810, having a housing 815 arranged atthe proximal end portion thereof. Distal baffles 829, an annular insert840 and nozzle insert 850, respectively define, in conjunction with thehousing 815, a fluid return plenum 821, a fluid supply plenum 841, acentral lumen 807 and a nozzle 855. The nozzle insert 850 is formed soas to have a depressed region 856 which helps accommodate a proximalsound attenuation chamber 891, in cooperation with a proximal capadapter insert 890. Sound absorbing material can be provided in thesound attenuation chamber 891 to help reduce noise emitted by theflowing fluid within the trocar 800B. The cap adapter insert 890 canfacilitate engagement between the trocar 800B and a cap, such as onecontaining a ball valve, for example.

A return fluid port 827 is formed through the housing 815 and is influid communication with the fluid return plenum 821. A fluid supplyport 883 is similarly formed through the housing 815 and is in fluidcommunication with the fluid supply plenum 841.

In each of the foregoing embodiments, fluid return plena have beenarranged distally, with respect to the fluid supply plena in each trocarembodiment. However, alternatively, the fluid return plenum may bearranged proximally, with respect to the fluid supply plenum. Such anarrangement is illustrated in connection with the trocar 900 illustratedin FIGS. 9A and 9B.

The trocar 900 of FIGS. 9A and 9B includes a body 910, an annular insert940 and a nozzle insert 950. A nozzle 955 is defined between the annularinsert 940 and the nozzle insert 950. A fluid supply plenum 941 isdefined in the housing 915 between the annular insert 940 and nozzleinsert 950 and is fed by fluid supply port 947. The fluid return plenum921 is defined proximal the nozzle insert 950, by the nozzle insert 950and an optional secondary seal element 980, secured to the housing. Thesecondary seal element 980 is secured to the housing and includes anannular seal 983 to facilitate sealing against instruments insertedthrough the lumen 907 of the trocar 900. If a complete seal is madebetween an instrument and the seal element, no fluid can escape throughthe proximal end of the lumen. Accordingly, if desired, the system thatprovides insufflation fluid for the purpose of creating a fluid seal inthe trocar 900, can be switched off for the duration during which a sealis maintained with the sealing element 980.

Baffles 991 and/or sound absorbent material can be arranged in the fluidreturn plenum 921 to reduce noise emitted from the trocar 900 when inuse. Fluid is exhausted from the fluid return plenum 921 through returnfluid port 993. The proximal cap 960 may be permanently or temporarilyaffixed to the remainder of the trocar 900, and includes a magnetic ballvalve, having a ball 967, which engages a ring 968 formed in the cap960. As embodied, either the ball 967 or the ring 968 can be magnetic,with the other being ferrous. Alternatively, the ring 968 can beembodied as an electromagnet, having power supplied thereto, with theball 967 being ferrous and therefore attracted to the ring 968electromagnetic ring when switched on.

Referring to FIG. 10, which illustrates a further embodiment of a trocar1000 in accordance with the invention, while forming a fluidic seal, thedistal motion of the gas is slowed and reversed to an outward flow as itis acted on by pressure within the abdomen. The gas, spent of inwardmomentum, is pushed proximally, normally through the lumen of thesurgical access device. As the spent gas exits the proximal end of thelumen 1020 of the surgical access device 1000, the gas, represented byarrows 1090, will enter a collection chamber 1030 which may also serveto house sound abatement material. The chamber 1030 will be connected toa return line via a port 1035 formed therein, through which arecirculation pump (e.g., pump 1940 of FIG. 19) will extract the exitinggas. During use, supplemental gas (e.g., carbon dioxide) can be added tothe system as needed, to insure that the net flow of gas through theproximal end 1010 of the access device 1000 is in the proximaldirection. This will ensure that the return flow to the recirculationpump is the desired gas (e.g., carbon dioxide) rather than air drawninto the access device 1000 through the proximal opening 1012. Dependingon the precise implementation, a mechanical valve can be provided at theproximal end of the surgical access device. Such a valve can act tofurther eliminate the potential of drawing external air into the systemfrom the outside.

FIGS. 11 and 12 are partial proximal end cross-sectional views of afurther embodiment of a trocar 1100 constructed in accordance with theinvention. The trocar 1100 includes a body 1110 having a proximalhousing 1115. The nozzle 1155 is formed between the housing 1110 and anozzle insert 1150, between which is also defined a fluid supply plenum1141. A safety valve 1180 formed in the housing 1115. In thisembodiment, a pressure sensing channel and plenum 1111 are formedbetween the body 1110 and a tubular member 1120 placed over the body1110.

The safety valve 1180 is configured so as to be urged closed by way of aspring (not shown), but alternate methods of maintaining the valve 1180closed by maintaining the ball 1181 in contact with a seat are possible.The safety valve 1180 is in fluid communication with the pressuresensing plenum 1111 by way of a fluid conduit 1184. When pressure withinthe abdominal cavity exceeds a predetermined safe limit, the ball 1181is urged away from its seat, the spring compressed, and thus the channel1184 is uncovered. Pressurized fluid then exits exhaust conduits 1185 a,1185 b and 1185 c. When the pressure in the abdomen subsequently drops,the valve 1180 closes.

The trocar 1100 of FIGS. 11 and 12 includes a cap 1170 removably securedthereto. The cap includes a chamber 1161 defined therein for use withsound attenuation features such as baffles and/or sound absorbingmaterial.

As shown in FIG. 13, which is a lateral cross-sectional view of the cap1170 of FIGS. 11 and 12, the body 1310 includes a track 1320, whichengages a mating track on the trocar 1100. A resilient locking member1330 engages a matching groove in the trocar 1100. Depressing the button1340 causes the locking member 1330 to deflect and open at its neck1331. This allows insertion onto and removal from the trocar 1100.

In further accordance with the invention, various systems for surgicalinsufflation and/or for use in creating and maintaining fluid seals incannulas constructed in accordance with the invention are provided.FIGS. 14-18 illustrate such systems.

In the embodiment of FIGS. 14 and 15A, which illustrate a system forsurgical insufflation and sealing, a control unit 1420 is shown inconnection with a surgical insufflator 1410 and a surgical trocar 1401,in accordance with one system embodiment of the invention. The trocar1401 is connected to the control unit 1420 by way of fluid conduits1480, and the insufflator is connected with the control unit 1410 by wayof another fluid conduit 1414. As shown in FIG. 15A, the insufflator1410 receives insufflation fluid from a source, in this case, a tank1580. A pressure regulator 1570 is provided between the tank 1580 andthe insufflator 1410.

The insufflator output is in fluid communication with a pressure sensingline 1481 leading to the trocar 1401, and with a pressure sensing line1581 leading to a pressure-controlled valve 1560, housed within thecontrol unit 1420. The control unit 1420 also includes a fluid pump 1550for recirculating insufflation gas for the purpose of maintaining afluid seal within the trocar 1401, and thus maintain thepneumoperitoneum within the abdomen 1598 of the patient.

The fluid is received from the trocar 1401 through return fluid conduits1485, 1585, is pressurized by the fluid pump 1550, and is directedthrough the fluid supply conduits 1583, 1483 to the fluid supply plenumand nozzle of the trocar 1401. If pressure within the abdomen 1598exceeds a predetermined safe limit, such increased pressure iscommunicated by way of the pressure sensing conduits 1481, 1581 to thepressure-controlled valve 1560. The pressure-controlled valve 1560 thenresponds by opening and short circuiting the fluid supply conduit 1583,through bypass conduit 1568, to the fluid return conduit 1585. Thus,fluid that was to be delivered to the trocar 1401 to maintain a fluidseal is reduced, and partially or fully recirculated back to the pump1550. Accordingly, excess fluid already within the abdomen 1598 willescape until abdominal pressure decreases to an acceptable level, whenthe valve 1560 closes and fluid flow through the fluid supply conduits1483, 1583 increases.

In the illustrated embodiment, a diaphragm-type valve, having aninternal diaphragm 1561, is shown, but it is to be understood thatalternate arrangements of pressure control are applicable to the presentinvention. For example, a pressure transducer can be arranged in fluidcommunication with the pneumoperitoneum, by placing the pressuretransducer on or in the trocar 1401, or in the control unit 1420, andcan be adapted and configured to control an electrically operated valve,for example.

Although illustrated as separate but connected units in FIG. 14, theinsufflator 1410 and the control unit 1420 can be contained in a singlehousing, as indicated by dashed line 1501 in the schematic of FIG. 15A,and as illustrated by element 1620 in FIG. 16. Connectors 1590 allowconnections between the control unit 1420 and fluid conduits 1481, 1483,1485, which in-turn connect to the surgical trocar 1401. Filters areprovided in line with the fluid conduits 1480, and can be housedindependently as with filters 1482 of FIG. 14, or in a single housing1682 of FIG. 16.

Insufflation gas is provided to the system 1400 from a supply, such as atank 1580. The system 1400, which can include elements such as aninsufflator 1410, pressure regulator 1570, conditioning elements, such ahumidifier, dehumidifier or heater, recirculation pumps and/or otherelements, receive the insufflation gas. The system 1400 can furtherinclude a safety dump valve in connection with one or more of the fluidconduits to exhaust excess insufflation fluid, if necessary.

Typical surgical insufflators operate by intermittently measuringpressure between periods of insufflation through a single fluid conduit.As embodied in FIGS. 14 and 15, the insufflator 1410 is capable offunctioning normally in this regard. The insufflator 1410 can initiateinsufflation of the abdomen 1598 through the pressure sensing conduit1481, and also intermittently measure pressure therethrough. However,normal insufflator operation does not adversely affect the functioningof the pressure-controlled valve 1560. Although slight pressure surgesmay be caused by the insufflator, a fluid seal in the trocar ismaintained.

Accordingly, in operation, when low abdominal pressure is sensed, theinsufflator is triggered to insufflate the abdomen 1598, and thepressure-controlled valve 1560 remains in a closed state, with the fluidpump 1550 receiving fluid from a return fluid plenum in the trocar 1401,through the return fluid conduits 1485, 1585, and delivering pressurizedfluid through the fluid supply conduits 1583, 1483 to the nozzle of thetrocar 1401.

When excessive abdominal pressure is experienced, the insufflator doesnot provide additional insufflation fluid to the abdomen 1598, and thepressure-controlled valve 1560 opens, connecting the fluid supplyconduit 1583 and the return fluid conduit 1585 through the bypassconduit 1568, thereby reducing the effectiveness of a fluid seal formedin the trocar 1401, and allowing a portion of the insufflation fluid toescape, and lowering the pressure within the abdominal cavity.

It may be desired to use a removable proximal end cap on the trocar1401, for use during insufflation to allow the insufflator 1410 to fillthe abdomen, after which time, the pump 1550 of the control unit 1420can be actuated, and the cap removed. Alternatively, an obturator can beinserted through the trocar 1401 and mutually sealed therewith, such asby O-rings or the like.

The system 1400 pressurizes the insufflation fluid to the desiredpressure and can be adapted and configured to treat or condition thefluid as necessary. As set forth above, the pressure supplied to trocarsin accordance with the invention can be between about 0 mmHg and 3500mmHg at any 0.1 mmHg increment of pressure therebetween. Such pressuresare suitable for fluid supply plena, such as plenum 141 shown in FIG. 2.However, relatively high pressures can also be supplied to the nozzlesof trocars in accordance with the invention, such as nozzle 155, bestseen in FIG. 3. In one embodiment, pressure supplied to the nozzle(s) isbetween about 1000 mmHg and about 2000 mmHg, and can be at any 0.1 mmHgincrement of pressure therebetween. In one preferred embodiment, thepressure supplied to the nozzle(s) is about 1530 mmHg. Naturally, normalpressures can vary as needed or desired. Moreover, pressures willdecrease from normal when an excessive abdominal pressure is measured,as set forth above.

FIG. 15B illustrates a system 1500, which is an alternate embodiment ofthe system 1400 of FIGS. 14 and 15A. The system 1500 is similar tosystem 1400, but simply additionally includes a safety pressure releasevalve 1599 in fluid connection with the pressure sensing line 1581. Incases of overpressure, in addition to the short-circuiting action of thepressure-controlled valve 1560, the safety pressure release valve 1599can additionally release insufflation fluid into the atmosphere. Thepressure setting at which the safety pressure release valve 1599 beginsto release fluid can be set so that it does not prematurely releasefluid, instead of the pressure-controlled valve 1560 recirculatingfluid. Accordingly, the pressure setting may be slightly higher than forthe pressure-controlled valve 1560.

With reference to FIG. 16, there is illustrated a control unit 1620which is connected to an insufflating trocar 1401, both in accordancewith the invention. A unitary filter element 1682 is provided, which isdescribed in more detail below in connection with FIGS. 20-22. Thecontrol unit 1620 can be utilized with any embodiments of the systemsdescribed in accordance with the invention, and can include, asillustrated, a settable control 1621 for setting the desired pressureoutput from the control unit 1620, and a pressure gauge 1625 forconfirming the set pressure. As illustrated, the filter 1682 mountsdirectly to the control unit 1620, with conduits integrally formed withthe housing of the filter 1682 being received by corresponding aperturesin the control unit 1620, as will be described in more detail below inconnection with FIGS. 20-22. As with other embodiments set forth herein,the control unit 1620 can be connected with a standard surgicalinsufflator or can be provided with insufflator componentry within thehousing of the control unit 1620.

FIGS. 17 and 18 illustrate an alternative embodiment of a system forsurgical insufflation and gas recirculation 1700. As with the embodimentof FIGS. 14 and 15, an insufflator 1410 and control unit 1420 are eachprovided. However, the insufflator 1410 and control unit 1420 in thisembodiment operate independently from one another, and eachindependently measures and responds to the abdominal pressure of thepatient. As with the embodiment of FIGS. 14 and 15, the trocar havingrecirculation capability 1401 is connected by way of fluid conduits 1480and filters 1482 to the control unit 1420. However, the insufflator1410, instead of being connected to the control unit 1420, is connectedby way of a fluid conduit 1780 to a secondary trocar 1701.

As shown in FIG. 18, insufflation gas is provided to the system 1700from a supply, such as a tank 1580. In operation, when low abdominalpressure is sensed, the insufflator 1410 is triggered to insufflate theabdomen, and the pressure-controlled valve 1560 remains in a closedstate, with the fluid pump 1550 receiving fluid from a return fluidplenum in the trocar 1401, through the return fluid conduit 1585, anddelivering pressurized fluid through the fluid supply conduit 1583 tothe nozzle of the trocar 1401.

When excessive abdominal pressure is experienced, the insufflator doesnot provide additional insufflation fluid to the abdomen, and thepressure-controlled valve 1560 opens, connecting the fluid supplyconduit 1583 and the return fluid conduit 1585 through the bypassconduit 1568, thereby reducing the effectiveness of a fluid seal formedin the trocar 1401, and allowing a portion of the insufflation fluid toescape, and allowing the pressure within the abdominal cavity.

With reference to FIG. 19, there is illustrated a system 1900 inaccordance with the invention in which surgical access devices 1905 areconnected via tubes 1920 to control equipment. In this case, controlequipment includes an insufflator 1960, and a control unit 1910, whichin turn is operably connected to a recirculation pump 1940, but whichmay include the pump 1940 within the housing of the control unit 1910.

In accordance with the invention, preferably all internal, gascontacting surfaces of the system, including tubing 1921, 1923, 1925 andportions of the recirculation pump 1940 are disposable. The pump 1940may be of a peristaltic design, pumping gas by flexing disposabletubing, such as by a compressive roller system. Alternatively, pumpingcan be accomplished by external manipulation of a closed, integral anddisposable diaphragm element. In accordance with the invention, it ispreferred that wetted surfaces be disposed of after each procedure as aprecautionary measure against cross-contamination. In alternateembodiments, systems in accordance with the invention can be providedwith other types of fixed displacement pumps, or a variable displacementpump, such as vane pump, for example.

The surgical access devices 1905 are connected to the insufflator 1960and control box 1910 by way of a pressure sense tube 1925. Pressurizedfluid is delivered to the surgical access devices 1905 by way of a fluidsupply tube 1921, while spent insufflation gas is retrieved by way of areturn tube 1923, each tube being connected through a control unit 1910.One or more intervening filters can be disposed between the accessdevices 1905 and the control unit 1910, as illustrated in FIGS. 16 and17.

A main fluid supply, such as a bottle of carbon dioxide gas, can beincorporated into the system 1900 in any suitable fashion, such as byproviding an input in the control unit 1910, for example.

Turning now to FIGS. 20-22, a filter assembly 1682 is illustrated. Thefilter assembly 1682 is provided with a housing 2080. The housing 2080can be molded in two parts to simplify assembly, and can hold within itfilter elements within separate, defined chambers corresponding to eachof a fluid supply, fluid return and pressure sensing and/or insufflationconduit. Due to the different flow rates and pressures passing througheach respective conduits, the filter size for that conduit is selectedaccordingly. As illustrated, particularly in FIG. 20, conduits 2089 areprovided in the housing 2080, each in fluid communication with a fluidpath and its respective filter element held within the housing 2080. Theconnection between the tubes and the filter 1682 can be any desired, andin accordance with the invention may be the same as the connectionbetween the trocar and tube set, as illustrated in FIGS. 23-25,described in further detail below.

FIG. 21 is an isometric view of the filter 1682, illustrating the tubeconnection conduits 2089, and the parts 2060, 2070 that comprise themajority of the filter housing 2080. The front lid 2060, with conduits2089 formed therein, is attached to the rear portion 2070, holdingtherewithin a plurality of filter elements for filtering fluid receivedfrom or provided to the trocar.

A fluid drain can be provided in one or more of the chambers definedwithin the housing 2080, particularly with the chamber 2084corresponding to fluid returned from the trocar. Such drain can in-turn,be connected to a central suction system to remove any collected fluid,or fluid can simply collect in the bottom of the housing 2080, or in aseparate reservoir. As embodied, this chamber 2084 is preferablyvolumetrically larger than the other two chambers to accommodate adepressurized, and thus expanded flow of fluid returning from thetrocar. The pressurized fluid being provided to the trocar takes up aproportionately lower volume, and accordingly, smaller filter chambersand tubes are sufficient to carry a given mass flow rate of insufflationfluid. When that same fluid is expanded upon its return, a largerconduit and filter chamber are necessary to handle the flow of fluid.

FIG. 22 is a side isometric view of the filter 1682, illustrating therear conduits 2287 defined in the rear portion 2070 of the housing 2080.The conduits 2287 are configured to mate with corresponding apertures ina control unit, and include sealing elements 2288, such as O-rings, andprotrusions 2289 for engaging a cooperating element in the housing tosecurely engage the filter 1682 to the control unit. Of course, thefilter 1682 can be embodied such that instead of mounting on a controlunit, the rear end of the filter connects to an intermediate tube set.

FIG. 23 illustrates two mating connection elements, including a boss2310, and an end connector 2320 for connecting a trocar 2301 inaccordance with the invention to a tube set (FIG. 24b ). The sameconnection arrangement can be used between the tube set and the filter,if so desired. A locking nut 2321 on the end connector 2320 engages anouter thread portion 2315 of the boss 2310, holding conduits 2329securely to the trocar 2301. The conduits 2329, particularly on the endmating with the corresponding apertures 2317 formed in the boss 2310,can be formed of a compliant material such that they self-seal againstthe inner walls of respective apertures 2317. Alternatively oradditionally, separate sealing elements can be utilized withoutdeparting from the spirit or scope of the invention. The generalconstruction of the threaded engagement can be that of a “luer lock,” isso-desired.

FIG. 24 is an isometric view of the mating side of the end connector2320. It is envisioned that a multi-lumen tube can be used with thesubject connector 2320 and systems of the invention. It is to beunderstood that the connector 2320 and systems in accordance with theinvention can function utilizing separate tubes, however a multi-lumentube can be provided to simplify procedures in the operating room and toreduce encumbrances to the surgical team. The multi-lumen tube can beextruded in one step as a unitary component. Alternatively, themulti-lumen tube can be formed as separate tubes which are then boundtogether in a suitable manner, such as by fusing adjacent walls to oneanother, or by over-wrapping the tube with another material. Moreover,strain relief elements can be molded into, over-molded onto or otherwiseapplied to the tube set across its entire length, or at one or more ofthe ends thereof. Such strain relief elements can include metal orrelatively rigid polymeric elements, such as coils, which resist strainof the assembly to inhibit kinks in the tube or to prevent damagethereto. It is to be understood that the entire cross-sectional lengthof the tube is in a preferred embodiment, contiguous and unbroken. Thetube can be of any length desired, but will typically range from betweenabout 2 to 4 meters in length for single main tubes. In alternateembodiments, conduits can be branched off therefrom, as needed to supplymultiple devices. It is further conceived that for this purpose, amanifold adapter can be provided for splitting flows between a controlunit and a surgical device, for example.

An alternate tube set may be provided having a dual-lumen tube portion,and a separate single lumen portion, which can be used, for example, forpressure sensing and/or insufflation functions. The alternative featuresdiscussed above in connection with the multi-layered tube set areapplicable to this tube set. Advantageously, a separate insufflationand/or pressure sensing tube allows for alternate and remote placementof one or both of these functions. This can also reduce the overall sizeof access devices of the invention, as integration of an insufflationand/or pressure sense channel therewith is not needed.

FIG. 25 illustrates a trocar 2500 including a body 2510, having ahousing 2515 arranged at the proximal end portion thereof. An annularinsert 2540 and a nozzle insert 2550 define, in conjunction, a nozzle2555 and a fluid supply plenum 2541. A fluid return plenum 2521 isdefined between two inserts 2520 and 2530. Seals, 2552, such as O-ringscan be provided in respective detents to seal between the inserts andthe housing 2515. The nozzle insert 2550 is formed so as to have adepressed region which helps accommodate a proximal sound attenuationchamber 2561, in cooperation with a proximal cap 2560. Sound absorbingmaterial can be provided in the sound attenuation chamber 2561 to helpreduce noise emitted by the flowing fluid within the trocar 2500. Agrating insert 2570 can be provided to help hold in and protect thesound attenuating material, and help further absorb excess sound.

The cap 2560, as illustrated, is adapted to threadedly engage thehousing 2515 by way of mating threads 2565 formed on the housing 2515and cap 2560. When assembled, screwing the cap 2560 to the housing 2515causes all inserts to be firmly held within the housing 2515, providingfor simple assembly of the trocar 2500.

The fluid return plenum 2521, fluid supply plenum 2541 and pressuresense and/or insufflation plenum 2511 are in fluid connection withrespective conduits, which are connected through the connection boss2310 provided on the housing 2515. The connection boss 2310, asdescribed above, connects with a tube end connector 2320 to facilitatefluid supply to and removal from the trocar 2500.

FIGS. 27 and 28 are schematic illustrations for alternate systems 2700,2800 in accordance with the invention. The systems 2700, 2800 of FIGS.27 and 28, can be incorporated integrally with a surgical insufflatorsimilar to the embodiments of FIGS. 15A and 15B, or may be independentof a surgical insufflator like the embodiment of FIGS. 17 and 18, withthe insufflator 1410 and control unit 1420 operating independently fromone another, and each independently measuring and responding to theabdominal pressure of the patient.

In each embodiment, the trocar having recirculation capability 2701 isconnected to an insufflator 2710, a pump 2750 and a valve. In theembodiment of FIG. 27, the valve 2760 is a back pressure control valve,which permits pressure on the upstream side of the valve 2760 only up toa certain preset value. When pressure in supply the conduit 2783 exceedsthe set value, it short-circuits to the return line 2785. This lowersthe supply pressure and reduces or shuts off the fluid seal created bythe pressurized flow entering the trocar 2701, thereby allowinginsufflation fluid in the abdominal cavity to escape through the lumenof the trocar 2701. Because the lumen of the trocar can be relativelylarge, such pressure can escape quickly, thereby preventing any harm tothe patient. Because the fluid is recirculated in the valve, a minimumof insufflation gas is wasted by dissipating it into the atmosphere.

The system 2800 of FIG. 28 includes an additional dump valve 2893 inconnection with the fluid supply conduit 2783. In addition to theshort-circuiting action of the pressure valve 2860 described above, thesystem 2800 is provided with a pressure sensor 2891, which can bemechanical but is, as illustrated, electronic. The pressure sensor 2891can be in fluid communication with the insufflation line or other sourceof abdominal pressure. When an over-pressure condition is sensed, thepressure sensor 2891 signals the dump valve 2893 to release fluid out ofthe system. As illustrated, the dump valve 2893 is electro-mechanical,but alternatively may be fully mechanical, as desired.

FIG. 28 is a schematic illustration of a recirculation system 2800 inaccordance with the invention. As with foregoing embodiments,insufflation gas is provided from a tank 2880 and pressure regulator2870 or other source, such as a central gas distribution system, forexample. As with foregoing embodiments, an insufflator 2810 is provided,and in this embodiment is connected by way of a pressure sense andinsufflation conduit 2881 to the trocar 2801. The pressure sense andinsufflation conduit 2881 is also in fluid communication with adiaphragm valve 2860, with internal diaphragm 2861 and movable spool2863. The spool 2863 is adjustably connected to the diaphragm, such thatthe spool moves in response to a change in abdominal pressure, asconducted through the pressure sense and insufflation conduit 2881. Thespool 2863 then opens and closes internal fluid paths A-F within thevalve 2860 body in response to the change in pressure, as will bedescribed in more detail below.

As with foregoing embodiments, a supply line 2883 and return line 2885are provided in connection with a recirculation pump 2850, for providingsupply fluid and for returning fluid for recirculation, respectively.Additionally, a supply bypass conduit 2889 leads from the supply line2883 to port D of the valve 2860, and an insufflation gas bypass conduit2887 is provided between the gas supply, such as a tank 2880, and port Eof the valve 2860.

The illustrated system 2800 is capable of controlling the fluidic sealformed in the trocar 2801. The system 2800 provides pressure to thetrocar 2801, resulting in constant abdominal pressure under normaloperation and acts as a safety valve, eliminating input pressure fromthe air seal under circumstances of excess pressure.

The system 2800 and valve 2860 are configured and adapted to regulatethe supply pressure to the trocar 2801 air seals so as to maintain aconstant, set pressure in the abdominal cavity, to slow the restorationfrom low pressure situations so as not to entrain excessive unwantedambient air into the abdomen, to flood the air seal entrance duringpressure restoration with the insufflation gas, such as carbon dioxide,to insure that entrained makeup gas is predominantly the desired gas,and to divert supply gas from the pressure supply line to the returnline, relieving excessive pressure which might otherwise harm thepatient.

The subject system 2800 and valve 2860 are capable of regulating thesupply pressure to the trocar air seals so as to maintain a constant,abdominal pressure within small tolerances, preferably to one mm Hg ofthe set pressure, under normal operation. The selected abdominalpressure is set by way of a calibrated adjustment knob, or alternativelyan electronic selector. In accordance with one aspect, the setting rangeis between about 5 to 18 mm Hg of abdominal pressure.

In the case of normal abdominal pressure during a surgical procedure,recirculation of insufflation gas through the pump 2850 and conduits2883, 2885 occurs normally, and no gas is sent through the bypassconduits 2887, 2887 from the pump or insufflation gas supply,respectively.

If abdominal pressure increases beyond a set point, which may occur dueto pressure placed on the insufflated abdominal cavity, for example, thespool 1963 moves in response to excess pressure on the diaphragm 1961and opens a fluid path between ports D and A, thereby opening the bypassconduit 2889, causing pressurized supply gas from the supply conduit2883 to be recycled to the return conduit 2885.

In accordance with one aspect, under high pressure circumstances, thevalve 2860 will divert all of the supply gas from the supply line 2883to the return line 2885 or exhaust (port F of the valve 2860) if theabdominal pressure exceeds the set pressure by a predetermined amount,which in accordance with one aspect of the invention is sixty percent.

If abdominal pressure continues to rise, displacement of the spool 2863causes a path between ports D and F to be opened, resulting in a “dump”of insufflation gas, which can be the operating room, or alternatively,a waste collection system. In such an instance, the pump 2850 is drawinggas from the trocar 2801, but little or no insufflation fluid is beingprovided back to the trocar, allowing abdominal pressure to safelyrevert to normal.

In the case of very low sensed abdominal pressure, which in a preferredaspect is any value 4 mm Hg or more below the set value, the spool 2863opens a path between ports D and B, to reduce flow to the nozzle of thetrocar, and thereby to reduce the severity of air entrainment from thesurrounding environment. Additionally or alternatively, the spool 2863opens a path from port E to port C to increase the concentration of pureinsufflation gas (typically carbon dioxide gas), and in that manner,flood the opening of the trocar 2801 with a high concentration of pureinsufflation gas. In this manner, any gas that is entrained through thetrocar 2801 will have a relatively high proportion of pure insufflationgas (e.g., carbon dioxide gas). Naturally, it is to be understood thatthe term “pure” may in fact be a mixture of gasses supplied to thesubject system, the intention being that such gas is drawn into theoperative space instead of surrounding gasses, which may have anundesirably high concentration of oxygen, other gasses or contaminants.

Although filtration elements are not explicitly illustrated in theembodiment of FIG. 28, it is to be understood that, as with any otherembodiments set forth herein, such elements can be provided at any pointin the system 2800 necessary, such as prior to entering the tubing tothe trocar, and when returning from the trocar. A filter element canalso be provided in-line with the insufflation and pressure sense line2881.

FIG. 29 is a schematic illustration of a recirculation system 2900 inaccordance with the invention, similar to that of the system 2800 ofFIG. 28. In the system 2900, instead of purely mechanical valve control,a combination of mechanical and electromechanical valves is used. Aswith the foregoing embodiment, a trocar 2801 having air-sealingcapability, a recirculation pump 2850, insufflation gas source 2880 andpressure regulator 2870 are provided. A supply line 2883 and return line2885 are provided and deliver pressurized insufflation fluid to anddeliver spent fluid from the pump 2850.

In the system 2900 of FIG. 29, a relief valve 2960 is provided, whichcontrols fluid flow through a bypass conduit 2986. As illustrated, thevalve 2960 is configured to respond to a situation where an inputpressure in the supply conduit 2883 is above a set pressure, however,the valve 2960 can be replaced by an active valve, such as theabove-described diaphragm valves that respond to abdominal pressure.

In the illustrated embodiment, in parallel with the relief valve 2960,is arranged an electromechanical valve 2993, which in the illustratedembodiment received input from a pressure sensor 2995. The pressuresensor 2995, naturally can take on any form, and can include interveningcontrols that allow a pressure threshold to be selected.

As with the system 2800 of FIG. 28, the valve 2993 provides for a bypassof the fluid being sent to the trocar 2801, as a supplement to thatprovided by the relief valve 2960. The valve 2993 also provides forsupplemental introduction of insufflation gas from the source 2880 atlow insufflation pressures to mitigate the effect of any entrainedambient air. That is, in accordance with this embodiment, when the valve2993 is triggered, flow is short-circuited from port C to port B,reducing flow to the nozzles in the trocar 2801, while port D is openedto port A, which increases the concentration of the desired insufflationgas—e.g., carbon dioxide gas.

Additionally, as with the foregoing embodiments, one or more filters canbe provided in the system 2900 to filter gas sent to or returning fromthe trocar 2801, if desired or required.

Advantageously, in accordance with the embodiments of FIGS. 28 and 29,the set point at which the valve controlling the flow of excess pureinsufflation gas, and the amount provided at that point, andproportional to any sensed pressure can be selected to as to balanceefficient use of pure insufflation gas with the proportion of gasseswithin the abdominal cavity of the patient. Additionally, such selectioncan be adjusted automatically during the surgical procedure. Forexample, one or more sensors can be provided in the systems 2900, suchas in conjunction with the return conduit 2885 and/or the insufflationconduit 2881. If an undesirably large proportion of oxygen, or otherunwanted gas, such as methane are detected, the system 2900 can beadapted to switch on supply of pure insufflation gas to displace the gasdetected within the abdominal cavity. In accordance with a preferredaspect, a minimum of 70% carbon dioxide gas is maintained in theabdominal cavity during a surgical procedure.

FIG. 30 illustrates a system 3000 in accordance with the inventionhaving an insufflation and recirculation unit 3010 and a plurality ofair-sealed trocars 3001 provided in a “daisy chain” arrangement. Asillustrated, one trocar 3001 is connected by way of a first tube set3082, and the other trocars are connected in-turn with second and thirdtube sets 3084. Each tube set includes at least a supply conduit, suchas conduit 2883, and a return conduit, such as conduit 2885, anddepending on the embodiment also a pressure sense and insufflationconduit, such as conduit 2881, for example. In accordance with theinvention, each trocar 3001 is in fluid communication with theinsufflation and recirculation unit through the respective tube sets.Fluid may flow through respective chambers provided on each of thetrocars, or alternatively through a channel provided in conjunction withthe tube sets. Such channel can be integrally formed with the tube sets,or provided as an add-on connector, so that tube sets in any combinationof desired lengths can be selected in an operating room.

Additionally, in accordance with any embodiment set forth herein,recirculation components and insufflation components can be provided ina common housing, or alternatively, a standard insufflator can be usedin conjunction with a recirculation device in order to achieve thefunctionality of the devices described herein.

FIG. 31 illustrates a system 3100 in accordance with the inventionhaving an insufflation and recirculation unit 3110 and a plurality ofair-sealed trocars 3101 provided in parallel. As illustrated, eachtrocar 3101 is connected by way of a tube set 3182 to the insufflationand recirculation unit 3110. Each tube set includes at least a supplyconduit, such as conduit 2883, and a return conduit, such as conduit2885, and depending on the embodiment also a pressure sense andinsufflation conduit, such as conduit 2881, for example. In accordancewith the invention, each trocar 3101 is in fluid communication with theinsufflation and recirculation unit through the respective tube sets. Atthe insufflation and recirculation unit 3110, each tube set is connectedby way of a distribution plenum 2913, which can be adapted andconfigured to allow connection of any number of air-sealed trocars inaccordance with the invention. For example it is conceived that it maybe desirable to have the capability to use up to six air-sealed portssimultaneously. Accordingly, the distribution plenum can be configuredto accommodate one, two, three, four, five, six or more air-sealedtrocars.

In accordance with the invention, insufflation gasses, such as carbondioxide gas can be fed into the systems on the suction side (prior toentering a pump), or on a supply side (after leaving the pump), or byway of a separate channel. Configuring the subject systems to take upreplacement fluid on the suction side, allows for better control of thefluid, as the pumps can be configured to deliver a relatively constantflow. On the other hand, if fluid is injected at irregular intervals onthe supply side of the pump, prior to being sent to the trocar(s) butafter the pump(s), pressure in the supply side of the system, and thusin the patient, may fluctuate undesirably. Because systems in accordancewith the invention are to a degree “open” systems, uptake of supplyfluid on a suction side of the pump(s) can be offset by a reduced amountof ambient air or abdominal air taken up by the system through thetrocar(s).

FIGS. 32 and 33 a and 33 b illustrate respective systems 3200, 3300 thatinclude, among other features, filter elements 3282 a; 3282 b; 3282 c oneach fluid conduit, and dual circulation pumps 3250 to circulate fluidthrough the respective system. In addition to providing redundancy, theplurality of pumps allow a larger volume of fluid to be circulated thana single pump of similar size. Further, such increased capacity ispossible with a reduced weight, as compared with a single largercapacity circulation pump. Also, if sized correctly, the pumps need notoperate at their capacity limits, which allows for improved efficiencyand reduced noise.

One or more heat exchangers (e.g., 3299 in FIG. 32) can be provided inconnection with the respective systems to help condition the fluid beingrecirculated so that, for example, very cold or very warm fluid is notreturned to the patient. Likewise, humidification and/ordehumidification elements can be included in the subject systems tocondition air upon return from a patient or prior to supply to thepatient. In accordance with one aspect of the invention, a heatexchanger 3299 is provided in connection with the system 3200 shown inFIG. 32, on the supply conduit 3283, leading from the recirculationpumps 3250. In accordance with this aspect, a heat exchanger can beprovided within and/or around the supply conduit 3283 to reduce thetemperature of pressurized fluid, upon exiting the recirculation pumps3250. This is particularly advantageous with increasing pressures, dueto the compression and maintenance of high pressures until reaching thetrocar 2801, where the fluid is eventually depressurized andrecirculated. Although some amount of heat from compression would belost prior to reaching the trocar 2801, a reduction in temperature soonafter compression may be desirable.

The heat exchanger can be embodied as a jacket around the supply conduit3283, utilizing a heat conductive material such as copper or aluminum,for example. The heat can be carried through a portion of the heatexchanger by way of conduction, or alternatively by way of an active orpassive thermodynamic circuit, such as one employing heat pipes, tocarry heat away from the supply conduit 3283, which can then betransferred to the surrounding environment in a suitable manner, whichcan include radiative, conductive and/or convective heat transfer, whichcan be aided by way of a fan, for example.

If desired, the heat exchanger 3299 can include elements within the flowpath of fluid passing through the supply conduit 3283, such as fins, toincrease the area through which heat transfer can occur. Applicantsconceive that the foregoing feature can also be provided in connectionwith any other embodiment described herein.

As illustrated in FIG. 32, a bypass or “back pressure” control valve3260 can be provided to dump supply fluid to a return, in cases ofexcess pressure. The valve is illustrated as being an adjustablemechanical valve, but can be provided at a set pressure threshold,and/or as an electromechanical valve in connection with compatiblepressure sensor. A gauge 3225 is optionally provided in connection withthe system 3200, and can be mounted on the face of a housing, and can bemechanical or electronic in nature, in which case a pressuresensor/sender can be provided in direct fluid contact with the internalfluid conduits of the system 3200.

Additionally, separate dump valves can be provided in systems of theinvention. Such valves can be provided for safety purposes, to reducerisk of over pressure scenarios. As set forth above, a bypass valve 3260can reduce fluid volume provided to the trocar 2801. A furtherinsufflation relief valve 3263 can be provided in connection with theinsufflation supply, to quickly relieve excess pressure in case ofoperator error, such as a severe occluding of the respective fluidconduit on the trocar 2801 or malfunction of the system, for example.The insufflation relief valve 3263 can embodied as a simple fixedmechanical relief valve, or alternatively as an adjustable relief valve.In either case, an equivalent electromechanical valve can be substitutedtherefor, if desired.

As with foregoing embodiments, a diaphragm valve 3261 or alternativelyan equivalent mechanical or electromechanical valve can be provided, butinstead of being used to dump fluid to a recirculation pathway (i.e.,the return conduit 3285), the fluid is released from the system, 3200 inresponse to cases of overpressure. Again, this valve 3261 can beembodied with an adjustable or a fixed pressure threshold.

As illustrated in the system 3200 of FIG. 32, a supply-side pressurerelief valve 3265 can be provided in connection with the high-pressureside of the fluid pumps 3250, to reduce pressure within the supplyconduit 3283 and connected components and conduits when the system 3200is switched off. This may be desirable because when the pumps 3250 ceaseoperation, fluid is not drawn through the return line 3285 from thetrocar 2801, but the supply conduit 3283 and associated components stillcontain pressurized fluid. As illustrated, the supply-side pressurerelief valve 3265 is a normally open electromechanical valve, allowingpressure to escape from the system 3200. When energized, the valve 3265closes to prevent pressure loss. As illustrated, the valve 3265 isenergized when the pumps 3250 are energized, and therefore can simply beconnected electrically in parallel therewith. Alternatively, the valve3265 can be controlled separately by an electronic controller to allowthe pumps 3250 to continue removal of fluid, such as insufflation gassesthat may include smoke or other debris, without reintroducing that fluidto the system 3200. Alternatively still, the pumps 3250 can beconfigured to reverse direction when an off-signal is received toequalize pressure in the supply 3283 and return 3285 conduits.Alternatively or additionally, the supply-side pressure relief valve3265 in connection with the pump(s) 3250 can be adapted and configuredto actively control output pressure across a range of selectablepressures, by reliving a portion or even all fluid during normaloperation, in response to the commanded output pressure.

In accordance with the invention, any of the foregoing valves can beeither mechanical or electromechanical in nature, as can the portionsthereof, or the related components, which are capable of sensingpressure.

As shown, FIG. 33a illustrates a system 3300 that is similar to thesystem 3200 of FIG. 32, with the exception that the mechanical diaphragmvalve 3261, which is configured to respond to a change in abdominalpressure, is replaced by a valve and sensor arrangement 3361. The valveand sensor arrangement 3361 can be adapted to act proportionately toactively control pressure to the trocar(s) and/or as a dump valve incases of sudden overpressure. As illustrated, the valve and sensorarrangement 3361 is a hybrid electro-mechanical and pneumaticallyoperated subsystem. A pressure regulator 3361 a is in fluidcommunication with the supply conduit 3283, and regulates pressure fromthat conduit, passing the reduced pressure fluid to a pilot valve 3361b, which receives a pressure signal from a pressure sense/insufflationconduit 3381, which is in fluid communication with the abdominal cavityof the patient. When the pressure in the abdominal cavity, as measuredthrough the pressure sense/insufflation conduit 3381 exceeds a setvalue, the pilot valve 3361 b responds by passing the reduced pressurefluid from the pressure regulator 3361 a to a dump valve 3361 c. Asillustrated the dump valve 3361 c releases fluid from the supply conduit3283 out of the system. However the dump valve 3361 c can alternativelybe passed to the return conduit 3285. Alternatively still, depending onthe magnitude of the pressure above the set pressure of the pilot valve3361 b, the valve and sensor arrangement 3361 can first pass fluid tothe return conduit 3285, and then if the pressure still exceeds adesirable limit, can release fluid from the system to the surroundingenvironment.

Further, the system 3300 of FIG. 33a can be provided with a venturidevice 3390 through which fluid from the insufflator is provided to thetrocar 2801. Although this feature can be applied to any embodiment setforth herein, as well as to any insufflator in the art, for simplicityit is described only in connection with FIG. 33a . As known, standardinsufflators alternately pulse pressurized insufflation fluid, withpressure readings being taken during rest intervals, which are necessaryto take relatively accurate readings, because taking readings duringinsufflation would yield inaccurately high results for abdominalpressures.

In accordance with the invention, an inlet port 3391 is the insufflationinput received from the insufflator (or similar device). An outlet port3393 is the output of the insufflation fluid to the trocar 2801. Apressure sensing port 3395 is the pressure sense conduit which isconnected to the pressure sense components, such as the pilot valve 3361b of the system 3300 of FIG. 33a , for example. Applicants recognizethat placement of a venturi-type device into a subject system, as shown,allows fluid communication between all devices as described above, butreduces or eliminates the fluctuation of measured pressure within thesystem normally caused by the relatively high intermittent pressurepulsations provided by the insufflator. With consistent and accuratepressure measurements, a single conduit can be utilized to both providecontinuous insufflation gas as needed and to simultaneously,continuously measure abdominal pressure.

Accordingly, the placement of such a venturi 3390 can enable constantinsufflation, rather than simply periodic insufflation availablecommercially today, and the concept and device can be easily applied tootherwise standard surgical insufflators.

It is further conceived, in accordance with the invention, that thesystems and devices described herein can be used for the purpose ofsmoke evacuation. The subject systems can be used as illustrated, andcan filter particulate matter from recirculated air, therebycontinuously cleaning the air within the abdominal cavity and allowing aclear view of the operative space.

If desired, nozzles and the associated supporting componentry can beprovided on one or more trocars as described hereinabove, e.g. trocar2801, while return insufflation fluid is collected through a seconddevice at a location spaced therefrom, to improve flow and better flushthe operative site of smoke and/or other debris. Devices that can beused to collect return fluid can include one or more trocars constructedin accordance with the invention (e.g., trocar 2801), or alternatively aconventional trocar, veress needle or the like.

In accordance with an another aspect, the subject systems can beconnected to more conventional access devices, with fluid being suppliedthrough an insufflation port or main lumen thereof. Also, fluid can besupplied through one device and collected at another device toeffectively filter the insufflation gas.

In alternative embodiments, fluid can be supplied to one conduit of aspecialized access device, while fluid is returned by way of a secondconduit associated with the access device, or vice versa. For example,if utilized with trocars in accordance with the invention, if thepressure sense/insufflation channel provided in the subject trocars issized sufficiently large, fluid can be supplied or returned through suchchannel, with the other function being performed through anotherchannel, such one or more of the recirculation chamber and the fluidsupply chamber and the associated components.

Optionally, the function of fluid supply or removal for smoke evacuationcan be effected by way of a separate tube inserted through a lumen of anaccess device, such as trocar 2801. Alternatively still, fluid supplyand or fluid return functions can be incorporated into a separatesurgical tool, that can be inserted through the lumen of an accessdevice, such as trocar 2801 or a more conventional access device, asneeded. If desired, such tool can remain in the lumen of the accessdevice during a procedure.

If so-desired, systems in accordance with the invention can be adaptedto recirculate and filter particulate matter without providing any netchange in abdominal pressure or volume. In such instances, theinsufflation componentry can be provided but temporarily disabled, whilealternative insufflation device is used to insufflate the abdominalcavity, for example.

Advantageously, however, the subject systems and related devices, suchas trocar 2801, for example, while being used to provide a fluid sealfor unencumbered access to the pneumoperitoneum inherently allow forexchange of gasses and recirculation thereof, which inherently providescontinuous cleansing by filtration of insufflation gases. However, thesubject systems can be used as an adjunct to more conventional surgicalsystems to provide the function of smoke evacuation.

FIGS. 34 and 35 illustrate an adapter 3400 for adapting a multi-lumentube set for use in connection with the subject systems and devices(e.g., trocar 2801) for use with a standard insufflation needle,standard insufflation trocar or the like. The adapter 3400 includes amulti-lumen portion 3410 for connection with a tube set of theinvention, which multi-lumen portion 3410 is similar to and compatiblewith the connector portion (e.g. 2310 in FIG. 23) of trocars of theinvention. The adapter 3400 also includes a single lumen portion 3420for connection to a standard insufflation needle (e.g. veress needle),standard insufflation trocar or other device. The single lumen portion3420 can be adapted with the necessary connection features to connectwith the standard insufflation devices, such as a standard luer fittingwith a central lumen and threaded engaging portion. As best shown inFIG. 35, which is a cross-section of the adapter 3400, an internalchannel connects an insufflation lumen 3412 from its axial offsetposition in the multi lumen portion 3410 to a central position in thesingle lumen portion 3420, and in this manner allows the subject systemsto pass insufflation fluid, and thus the insufflator functionalitytherethrough. The fluid supply lumen 3413 and recirculation return lumen3411 (FIG. 34) are provided as terminations, but alternatively can beconnected to one another in the adapter 3400, bypassing the patient. Ifterminated as illustrated, the subject systems can bypass fluid supplyand return functions through internal bypasses, as described above.However, the adapter 3400 with standard insufflation needle, standardinsufflation trocar or other device can be used in parallel with asurgical access device or “trocar” in accordance with the invention,such as trocar 2801.

In use, an initial puncture and insufflation can be performed with useof a device, such as a veress needle, connected through the adapter340,0 to a system in accordance with the invention. When the desiredabdominal pressure is reached, one or more access devices can then beinserted into the patient and connected to a system in accordance withthe invention.

FIGS. 36-63 illustrate an embodiment of a surgical access device 3600designed in accordance with the invention, related components thereofshowing alternatives, as well as an insertion device 3890 (FIGS. 38-42).

FIGS. 36 and 37 illustrate opposite faces of the surgical access device3600, which, among other aspects, is adapted and configured to create afluidic seal, or in other words, a pressure barrier, between theabdominal cavity and the surrounding environment, as described hereinabove, and below. The access device 3600 includes, among othercomponents, a proximal housing 3615, a connector 3610 for engaging atube set for use therewith, and an outer body tube 3619. The proximalportion of the housing 3615 includes threads 3665 for connection with anend cap, such as end cap 3660, with additional examples shown insubsequent drawings and discussed below. The housing 3615 includesalignment elements 3619 a, 3619 b, which engage corresponding portionson the insertion device 3890 (FIGS. 38-42). As illustrated in FIGS. 36and 37, two pairs of alignment elements 3619 a, 3619 b are provided onopposite portions of the housing 3615, although variations thereof arepossible. The angled orientation of the alignment elements 3619 a, 3619b is such that the mating portion of the insertion device 3890 isgradually guided into alignment as the access device 3600 and insertiondevice 3890 are connected.

As illustrated in FIG. 38-42, the insertion device 3890 includes apenetration tip 3898, attached by a shaft 3999 (FIG. 39) to a handleportion 3891. A grip 3895 b and indentations 3895 a are included on thehandle 3891 to facilitate holding by the surgeon. The surgeon's firstfinger and thumb rest in the indentations 3895 a provided on each sideof the handle 3891, with the second and third fingers resting on thegrip 3895 b, for example. The distal end portion of the handle 3891(toward the left in FIG. 38) includes shaped openings 3896, providedsymmetrically on each side of the handle. As shown in FIG. 40, theshaped openings 3896 allow the connection element to sit more proximally(toward the handle 3891), reducing the overall profile of the combinedassembly of the access device 3600 and insertion device 3800. The shapedopenings 3896 also permit the use of the angled alignment elements 3619a, 3619 b that guide the proper mutual alignment between the accessdevice 3600 and insertion device 3890. The alignment elements 3619 a,3619 b and mating portion of the handle 3890, in accordance with apreferred aspect, are sized, spaced and/or shaped to permit only properrelative orientation of the access device 3600 and insertion device3890.

As illustrated, the insertion device 3890 includes dual opposedengagement catches 3894, which have pawls 3893 on their distal ends, andpivots 3892 in the middle portions thereof. The pawls 3893 engage alower portion of the housing 3615 or other mating surface, depending onthe precise implementation. A scope or instrument lock 3897 can also beprovided for engaging a device such as an endoscope, for use inconjunction with the insertion device 3890. Alternate features can beprovided, as set forth in U.S. Patent Publication Numbers 2008/0086080to Mastri et al. and 2008/0086160 to Mastri et al., which areincorporated herein by reference in their entirety.

FIG. 39 illustrates a partial cutaway view of the insertion device 3890shown with the access device 3600 engaged therewith. The shaft 3999 ofthe insertion device 3890 extends through a central lumen of the accessdevice 3600, terminating in the penetrating tip 3898. The pawls 3893 ofthe catches 3894, which are mounted on pivots 3892 are seen engaging theaccess device 3600. The outer surface of the scope or instrument lock3897 is also illustrated.

FIGS. 41 and 42 respectively illustrate top and bottom views of theaccess device 3600 in connection with the insertion device 3890. As bestseen in FIG. 41, the handle of the insertion device 3890 includes anaperture 4102 formed therein, which allows an endoscope or otherinstrument to pass therethrough, which can be engaged by the lock 3897.

FIGS. 43-63 illustrate various aspects and alternatives for the trocar3600 in accordance with the invention.

As shown in FIGS. 43-45, the trocar 3600 includes a body having ahousing 3615 arranged at the proximal end portion thereof. An annularinsert 3640 and a nozzle insert 3650 define, in conjunction, a nozzle3655 and a fluid supply plenum 3641. A fluid return plenum 3627 isdefined between two inserts 3620 and 3630. The upper insert 3630includes a plurality of apertures 3631, 3633 defined therein, whichallow the upper insert 3630 to guide instruments inserted therethroughwhile effectively raising the location proximally at which fluid istaken in by the return plenum 3627. The configuration and placement ofthe apertures 3631, 3666, therefore, can be adjusted as needed tofine-tune the operational characteristics of the trocar 3600.

In the illustrated embodiment, the lower insert 3620 is substantiallytubular and extends distally toward the end of the access device 3600,and in part defines, with the housing 3615, an insufflation and/orpressure sense conduit 3611 for communicating the pressure of theabdominal cavity with the external system components. Seals, such asO-rings can be provided in respective detents to seal between theinserts and the housing 3615, to help seal respective chambers from oneanother.

The nozzle insert 3650 is formed so as to have a depressed region whichhelps accommodate a proximal sound attenuation chamber 3661, incooperation with a proximal cap 3660. Sound absorbing material can beprovided in the sound attenuation chamber 3661 to help reduce noiseemitted by the flowing fluid within the trocar 3600. Openings 3670 areoptionally provided in the cap 3660 to allow communication between thefluid in the lumen and any sound attenuation materials provided in thechamber 3661 to allow the material to absorb sound created in the lumen3607 of the access device 3600. The cap 3660 then helps guide instrumentinsertion, while holding in and protecting the sound attenuatingmaterial, and help further absorb excess sound.

The cap 3660, as illustrated, is adapted to threadedly engage thehousing 3615 by way of complimentary threads 3665 formed on the housing3615 and cap 3660. When assembled, screwing the cap 3660 to the housing3615 causes all inserts (3620, 3630, 3640, 3650) to be firmly heldwithin the housing 3615, providing for simple assembly of the trocar3600. Alternatively, the cap 3660 can be secured to the housing in adifferent manner, including but not limited to other mechanicalconnections, such as latches, snaps, friction fit, adhesives, welding,such as heat or friction welding, including spin-welding, for example.

The fluid return plenum 3627, fluid supply plenum 3641 and pressuresense and/or insufflation plenum 3611 are in fluid connection withrespective conduits, which are connected through the connection boss3610 provided on the housing 3615. The connection boss 3610, asdescribed above, connects with a tube end connector, such as connector2320 to connect the trocar 3600 with a compatible system to facilitatefluid supply to and removal from the trocar 3600.

As best seen in the enlarged view of FIG. 45, the insufflation and/orpressure sense conduit 3611 which is defined between the lower insert3620 and the housing 3615 continues distally through the trocar 3600. Asseen in FIGS. 36-42, for example, apertures 3623 are provided on theouter surface of the trocar 3600 in fluid communication with theinsufflation and/or pressure sense conduit 3611, and as best seen inFIGS. 43 and 45, apertures 3625 can be provided in the inner wall of thetrocar 3600, in communication with the lumen 3607 and the insufflationand/or pressure sense conduit 3611. Accordingly, with redundantapertures, any attached system or device has an improved chance of notreceiving an inaccurate reading or being inhibited from proper function.In case an instrument inserted through the lumen 3607 partially or fullyblocks the inner apertures 3625, the outer apertures 3623 are stillavailable to conduct fluid and/or a pressure signal. Similarly, if theouter apertures 3623 are blocked by tissue, or other structures orobjects in the abdominal cavity, the inner apertures 3625 are available.

FIG. 46 illustrates an upper portion 3620 a of the lower insert 3620,embodied separate from a distal end portion 3620 b (See FIG. 50)thereof. As illustrated, the upper portion 3620 a includes aperturesembodied as notches 4629, to allow passage of fluid collected in therecirculation plenum 3627 to pass through the insert 3620 and to therespective system for filtration, exhaust and/or recirculation, asdesired.

FIG. 47 is an isometric view of the upper insert 3630 shown alone,illustrating the various apertures 3631, 3633, as described above. FIG.48 is an isometric view of the cap 3660 as described above, whichincludes apertures 3670 embodied as slits to facilitate absorption of atleast a portion of sound generated by fluid flowing in the trocar 3600.FIG. 49 illustrates an insert 4963 formed of sound-absorbing material,for placement beneath the cap 3660, in the proximal sound attenuationchamber 3661 (FIGS. 43 and 44). The material can be any desiredsound-absorbing material, including foams, and may be shaped as solidblock, or shaped to enhance sound attenuation properties, which mayinclude increasing surface area. Such shapes can include but are notlimited to having a substantially honeycomb structure, undulatingsurfaces, a surface having conical protrusions, tubular passagewaysformed therethrough, or the like.

FIG. 50, as set forth above, illustrates the distal end portion 3620 bof the lower insert 3620, wherein the proximal portion 3630 a (See FIG.46) is formed separately therefrom. As illustrated, internal apertures3625 are formed in the distal end region of the distal end portion 3620b, for the reasons set forth above.

FIG. 51 illustrates the substantially annular insert 3640, which incombination with the nozzle insert 3650 (See FIG. 52, for example) formsnozzles 3655, through which pressurized fluid passes and is manipulatedto form a fluidic seal or “barometric barrier,” for preventing loss ofpressurization of the abdominal cavity during a procedure, whileallowing for a substantially physically unobstructed access path intothe surgical cavity. The nozzle insert 3650, as illustrated, includesstandoffs 5147 to help maintain spacing between the substantiallyannular insert 3640 and the nozzle insert 3650, arranged thereabove, asseen, for example, in FIGS. 43 and 44. The standoffs 5147 are spacedapart from one another to allow pressurized fluid to flow therethroughfrom the fluid supply plenum 3641, through the nozzle 3665. A diverter5148 is also provided in the illustrated embodiment and is aligned witha pressurized fluid inlet to diffuse an incoming stream of fluid withinthe fluid supply plenum 3641, to more effectively distribute fluid flowabout the plenum 3641, and thus through the nozzle 3665.

FIGS. 52a and 52b illustrate isometric and detail views, respectively,of a nozzle insert 3650 in accordance with the invention, in whichradially spaced depressions 5253 are formed in the lower portion 5258 ofthe insert 3650 to define, in combination with the annular insert 3640,fluid passageways for the nozzle 3665. The depth of the depressions 5253can solely determine the area through which fluid can pass if theannular insert 3640 and nozzle insert 3650 are provided in intimatecontact, and fluid cannot pass between the insert 3640 and nozzle insert3650, except through the depressions 5253. In accordance with onepreferred embodiment, the depth of the depressions 5253 is about 3/1000inch (about 0.0762 mm), however the precise depth can be adjusted asneeded. Alternatively, spacers, including the above-mentioned standoffs5147 help define the spacing between the annular insert 3640 and thenozzle insert 3650, and determine the width of a space between theinsert 3640 and nozzle insert 3650, and therefore the area available forfluid to pass through the nozzle 3665.

The lower portion 5258 of the nozzle insert 3650 includes asubstantially cylindrical outer portion 5259, in which the depressions5253 are formed. As illustrated, six depressions 5253 are provided. Thedepressions 5253 include a bottom portion 5254 and side portions 5257.The bottom portion 5254 can be either substantially flat or arcuatelycurved, as shown in FIG. 52b . In the case of an arcuately curved bottomportion 5254, the radius of the curvature can be substantially the sameas a radius of curvature of the substantially cylindrical outer portion5259, but offset radially centrally, for example, forming thedepressions 5253. The side portions 5257, then, are contoured so as notto promote turbulence or noise, and to facilitate substantially smoothflow of fluid from the fluid supply plenum 3641 through the depressions5253 and the nozzle 3665. Fluid flow though the depressions 5253 andaround the distal portion of the insert 3650 tend to behave inaccordance with the Coanda effect, which directs the fluid streaminwardly, in accordance with the inward curvature of the distal tipportion 5256 of the insert 3650.

FIGS. 53-57 illustrate an alternate construction of a nozzle andassociated components for a trocar in accordance with the invention. Thenozzle assembly 5300 includes a lower substantially annular insert 5340,and an upper nozzle insert 5350. Standoffs 5357 are provided to spacethe components and to allow fluid to pass therethrough, which in theillustrated embodiment are provided on the nozzle insert 5330 (FIG. 56).As with the above-described embodiment, a diverter 5348 can be providedand aligned with a pressurized fluid inlet to diffuse an incoming streamof fluid within the fluid supply plenum 3641, to more effectivelydistribute fluid flow about the plenum 3641, and thus through the nozzle3665.

As best seen in FIGS. 54-56, a nozzle spacer 5554 is provided to helpdefine a nozzle in trocars according to the invention. The nozzle spacer5554 is placed between a compatible annular insert 5340 and nozzleinsert 5350. As illustrated, a plurality of standoffs 5357 are providedon the nozzle insert 5350, while a diverter 5348 is provided on theannular insert 5340, although these elements can be embodied separatelyor on one or the other component. The nozzle spacer 5554 is provided tomaintain a consistent width of the nozzle 3655. As describedhereinabove, the nozzle 3655 can be essentially a continuous annulus.Alternatively, as shown in FIGS. 53-57, the nozzle 3665 if formed of anannular array of discrete jets that coincide with notches 5552 (FIG. 55)of the nozzle spacer 5554, between the annular insert 5340 and thenozzle insert 5350. The thickness of the tabs 5551 of the nozzle spacer5554 determines the width of the nozzle 3655 in such an arrangement. Inaccordance with the invention, the nozzle spacer 5554 can be formed of ametal, formed as by stamping, so as to ensure relatively tighttolerances. In accordance with one exemplary embodiment of theinvention, the thickness of the nozzle spacer 5554 is about 3/1000 inch(about 0.0762 mm). Although other materials can be used to form thespacer 5554, metal is capable of providing a more predictable nozzlewidth than molded polymeric components, which may be susceptible tomolding irregularities or other irregularities encountered duringmolding. As illustrated in FIGS. 56 and 57, for example, the standoffs5357 can serve to align and maintain the position of the nozzle spacer5554 in the assembly 5300. Such positional constraint can server topromote the overall stability and durability of the assembly 5300 andthe trocar in which it is provided, as a whole.

FIG. 58-63 illustrate optional proximal cap assemblies and associatedfeatures. Such caps can be used to close off the proximal end of thelumen of trocars in accordance with the invention, when desired toreduce noise in the operating room and/or to reduce loss of insufflationfluid to the operating room, for example.

FIGS. 58-59 illustrate a cap 5800 without integral sound attenuationmaterials, having an outer housing portion 5860, an actuation ring 5865,and a shutter 5861. The actuation ring 5865 includes an extension 5863,which extends through the housing portion 5860, and is moved by the userto rotate the actuation ring 5865, to pivot the shutter 5861 axiallycentrally. In the cap 5800, all components are secured from above to thehousing portion 5860. When the shutter is open, it does not obstruct thelumen of the trocar, and when the shutter 5861 is closed, the lumen isclosed off. When the actuation ring 5865 is rotated, slots 5901 definedtherein ride on pins 5905 extending from the housing portion 5860, whichallow a mating portion of the shutter 5861, in this case, a pin 6109,engaged in a mating aperture formed in the actuation ring 5865 to causeaxially central rotation of the shutter 5861. The mating aperture in theactuation ring 5865 can be a matching hole, a straight or curved slot,or any feature necessary to allow the relative motion of the componentsas described. If desired, one or more resilient seals can be provided atthe juncture between the housing portion 5860 and the shutter 5861 toenhance a seal therebetween.

FIGS. 60-63 illustrate an alternate embodiment of a cap 6000 constructedin accordance with the invention designed to facilitate soundattenuation features, including internal sound attenuation materials.The cap 6000 again includes a shutter 5861, actuation ring 5865 andextension 5863. The housing portion 6060 includes sound attenuationapertures 3670 formed therein, the configuration of which can be asillustrated, or can vary therefrom, as desired or required. In the cap6000, the components of the shutter mechanism are mounted from below toa separate component, which in the illustrated embodiment is a modifiednozzle insert 6350. The modified nozzle insert 6350 includes posts toguide the moving parts of the cap 6000. The relative motion of thecomponents of the cap 6000 is similar to the above-described cap 5800.In each of the foregoing embodiments

It is to be understood that various alternate embodiments of caps inaccordance with the invention are possible. It is to be understood thatthe precise mechanism and placement of actuation portions can vary dueto design requirements. Moreover, incorporation of one or moremagnetically-responsive components is conceived, to allow actuation of ashutter by way of an external magnetic actuation device. Alternativelystill, cap features described in U.S. patent application publicationnumber US 2007/0088275, which is incorporated herein by reference in itsentirety, can be provided, including but not limited to features such asball valves and the like.

The devices, systems and related methods of the present invention, asdescribed above and shown in the drawings, provide for advantageoussystems for surgical insufflation and gas recirculation, and relateddevices and methods therefor. It will be apparent to those skilled inthe art that various modifications and variations can be made in thedevices, systems and methods of the present invention without departingfrom the spirit or scope of the invention. Thus, it is intended that thepresent invention include such modifications and variations.

What is claimed is:
 1. A surgical access device comprising: an elongatedouter tubular member having opposed proximal and distal end portions andhaving a longitudinal axis extending therethrough, the distal endportion of the outer tubular member having a radially inwardly tapereddistal tip section having an open distal end with an inner diameter; andan elongated inner tubular member having opposed proximal and distal endportions and being arranged coaxially within the outer tubular member,the inner tubular member having an open distal end with an innerdiameter and defining a central conduit, the central conduit extendingthrough the center of the surgical access device and extendinglongitudinally to the open distal end of the inner tubular member forpassage of a surgical instrument therethrough; wherein portions of theinner and outer tubular members are spaced apart to define an outerconduit for receiving gas; wherein a plurality of circumferentiallyspaced apart apertures extend through the distal end portion of theouter tubular member and are in communication with the outer conduit fordispensing gas; wherein an outer surface of the distal end portion ofthe inner tubular member is in direct contact with an inner surface ofthe distal end portion of the outer tubular member to enclose a distalend of the outer conduit at a location where an inside diameter of theouter tubular member is smaller than an inside diameter of portions ofthe outer tubular member that are spaced apart from the inner tubularmember; wherein the open distal end of the outer tubular member islocated beyond the open distal end of the inner tubular member; whereinthe open distal end of the outer tubular member is in a plane that isperpendicular to the longitudinal axis thereof; and wherein the innerdiameter of the open distal end of the outer tubular member is equal tothe inner diameter of the open distal end of the inner tubular member.2. The surgical access device as recited in claim 1, wherein the distalend portion of the inner tubular member defines a plurality ofcircumferentially spaced apart apertures extending through the innertubular member to provide communication between the outer conduit andthe central conduit.
 3. A surgical access device comprising: anelongated outer tubular member having opposed proximal and distal endportions and having a longitudinal axis extending therethrough, thedistal end portion of the outer tubular member having a radiallyinwardly tapered distal tip section having an open distal end with aninner diameter; an elongated inner tubular member having opposedproximal and distal end portions and being arranged coaxially within theouter tubular member, the inner tubular member having an open distal endwith an inner diameter and defining a central conduit extending to theopen distal end for passage of a surgical instrument therethrough;wherein portions of the inner and outer tubular members are spaced apartto define an outer conduit for receiving gas; wherein a plurality ofcircumferentially spaced apart apertures extends through the distal endportion of the outer tubular member and are in communication with theouter conduit for dispensing gas; wherein an outer surface of the distalend portion of the inner tubular member is in direct contact with aninner surface of the distal end portion of the outer tubular member toenclose a distal end of the conduit at a location where an insidediameter of the outer tubular member is smaller than an inside diameterof portions of the outer tubular member that are spaced apart from theinner tubular member; wherein the open distal end of the outer tubularmember is located beyond the open distal end of the inner tubularmember; wherein the open distal end of the outer tubular member is in aplane that is perpendicular to the longitudinal axis thereof; andwherein the inner diameter of the open distal end of the outer tubularmember is equal to the inner diameter of the open distal end of theinner tubular member.
 4. The surgical access device as recited in claim3, wherein the distal end portion of the inner tubular member defines aplurality of circumferentially spaced apart apertures extending throughthe inner tubular member to provide communication between the outerconduit and the central conduit.
 5. A surgical access device comprising:an elongated inner tubular member having opposed proximal and distal endportions and having a longitudinal axis extending therethrough, theinner tubular member defining a central conduit having an open proximalend and an open distal end with an inner diameter, the open proximal endof the central conduit and the open distal end of the central conduitbeing centered around a longitudinal central axis of the device forpassage of a surgical instrument therethrough, the inner tubular memberhaving an outer surface; an elongated outer tubular member havingopposed proximal and distal end portions and being arranged coaxiallyabout the inner tubular member, the inner tubular member and the outertubular member defining an outer conduit therebetween for receiving gas,the outer tubular member having an inner surface; wherein the outersurface of the distal end portion of the inner tubular member and theinner surface of the distal end portion of the outer tubular member arein direct surface to surface contact with one another such that thedistal end portion of the inner tubular member and the distal endportion of the outer tubular member cooperate with one another toenclose a distal end of the outer conduit; wherein a distal end sectionof the distal end portion of the outer tubular member is radiallyinwardly tapered, located beyond a distal end of the inner tubularmember, and has an open distal end with an inner diameter; wherein thedistal end portion of the outer tubular member defines a plurality ofapertures extending through the outer tubular member in fluidcommunication with the outer conduit for dispensing gas; wherein theopen distal end of the outer tubular member is in a plane that isperpendicular to the longitudinal axis thereof; and wherein the innerdiameter of the open distal end of the outer tubular member is equal tothe inner diameter of the open distal end of the inner tubular member.6. The surgical access device as recited in claim 5, wherein the distalend portion of the inner tubular member defines a plurality ofcircumferentially spaced apart apertures extending through the innertubular member to provide communication between the outer conduit andthe central conduit.
 7. A surgical access device comprising: a) anelongated outer tubular member having opposed proximal and distal endportions and having a longitudinal axis extending therethrough, thedistal end portion of the outer tubular member having a radiallyinwardly tapered distal tip section having an open distal end with aninner diameter; b) an elongated inner tubular member having opposedproximal and distal end portions and being arranged coaxially within theouter tubular member, the inner tubular member defining a centralconduit extending to an open distal end that is axially aligned with theopen distal end of the outer tubular member, wherein the central conduitof the inner tubular member and the open distal end of the outer tubularmember are dimensioned and configured for passage of a surgicalinstrument therethrough; c) an outer conduit defined between the innerand outer tubular members for receiving gas; and d) a plurality ofcircumferentially spaced apart apertures extending through a distal endportion of the outer tubular member in communication with the outerconduit, wherein an outer surface of the distal end portion of the innertubular member and an inner surface of the distal end portion of theouter tubular member are in direct surface to surface contact with oneanother so that the distal end portion of the outer tubular member andthe distal end portion of the inner tubular member cooperate with oneanother to enclose a distal end of the outer conduit, wherein the opendistal end of the outer tubular member is located distal to the opendistal end of the inner tubular member, and wherein the open distal endof the outer tubular member is in a plane that is perpendicular to thelongitudinal axis thereof, and wherein the inner diameter of the opendistal end of the outer tubular member is equal to an inner diameter ofthe open distal end of the inner tubular member.
 8. The surgical accessdevice as recited in claim 7, wherein the distal end portion of theinner tubular member defines a plurality of circumferentially spacedapart apertures extending through the inner tubular member to providecommunication between the outer conduit and the central conduit.